1. Introduction: instructions to contributors notes from the editor
2. Lotus Activities: reports and abstracts
3. Recent Current Literature
Please answer the following questions
to help update the mailing list and provide information about
your research interests.
Name _______________________________________________________
Institute or Agency _____________________________________________
Mailing Address _______________________________________________
Mailing Address _______________________________________________
Mailing Address _______________________________________________
Country _____________________________________________________
Telephone Fax ________________________________________________
E-mail ______________________________________________________
Checkmark all categories
that apply to your area of Lotus research:
| O Genetics | O Breeding | O Taxonomy | O Physiology |
| O Pathology | O Ecology | O Biology | O Forage |
| O Utilization | O Germplasm | O Tissue culture | O Biotechnology |
| O Entomology | O Seed | O Reclamation | O Other (please indicate) |
List the Lotus
species you study: _______________________________
Give a brief description of your research _________________________
___________________________________________________________
Suggestions? _______________________________________________
Send or FAX your completed questionnaire to:
P. R. Beuselinck, USDA-ARS
University of Missouri
207 Waters Hall
Columbia, MO 65211 USA
FAX 573-882-1467
Purpose:
The Lotus Newsletter consists of informal
communications of research information on Lotus spp. Reports
of any phase of research on Lotus breeding, genetics, taxonomy,
management, utilization or physiology are welcome. Your biographic
sketches and information about your research objectives, approaches,
and progress including titles of your publications are encouraged.
Seed requests and news items are accepted.
This is the 28th year of publication for the
Lotus Newsletter. Now is the time
to consider contributing to the 29th volume of the Lotus
Newsletter. Contributions generally are compiled without
editing.
1. Prepare your contribution using any IBM (MS-DOS) or Macintosh word processing program. Then you have two options:
a. submit the file on 3.5 " (90 mm) disk accompanied by a printed copy of the contribution. Identify which program you used. OR
b. submit the file to my e-mail address (pbeuselinck@plantsci.missouri.edu)
and send me a hardcopy by FAX to 573-882-1467, or by regular mail.
1. Single space typewritten text on white 8.5" x 11" (21.5 cm x 27.5 cm) paper. Double space between paragraphs and tables. Do not number pages.
2. Leave a minimum of 3/4" (1.9 cm) on the left and bottom of each page.
3. On the first page of each contribution, indicate state or country, title of report, and name(s) of contributor(s).
4. Send your contributions by December 31,
1997 to:
Lotus Newsletter
Dr. P. R. Beuselinck, USDA-ARS
Plant Genetics Research Unit
207 Waters Hall
University of Missouri
Columbia, MO 65211 U.S.A.
E-mail: pbeuselinck@plantsci.missouri.edu
FAX 573-882-1467
Many thanks to you who respond to my requests for information about your Lotus research. Your contributions to the Lotus Newsletter help generate a better perspective of the international research and management on the many species of Lotus.
You have successfully accessed the Lotus Newsletter homepage. If you need a hardcopy you can print a copy for yourself or you simply read the volume of your choice without filling your bookshelf. My goal is to work my way back through all the volumes until they are all in electronic format.
From the homepage you should be able to access the current volume or past volumes. The current volume for the year will be a compilation of all Lotus news and articles received between January 1 through December 31.
The internet address for the Lotus Newsletter is: http://www.plantsci.missouri.edu/lnl
If you have not filled-out and sent in a questionnaire in the last two years please complete one. If you know of others interested in the Lotus Newsletter have them submit a questionnaire and they'll be added to the mailing list.
The illustration on the cover is of Lotus glaber Mill. has again been graciously provided by Ana Arambarri (Argentina) . The Lotus illustration is the 5th in a series of illustrations that started with Volume 23. Many scientists are familiar with the name of this species to be Lotus tenuis Waldst. et Kit. Note that according to the International Code of Botanical Nomenclature the correct nomenclature is Lotus glaber Mill.
Introduction
In a plant breeding material of Lotus glaber it was observed,
in two successive generations, the presence of a lower frequency
of individuals that were differentiated with regard to the typical
phenotype by numerous characteristics. Among these are underlined
waved branches and larger leaflets. Individuals of both phenotypes
were cloned and it has been begun a comparative study of characters
with possible agronomic importance.
According to Tichá (1985), the stomatal density and size
are important anatomical parameters that contribute to the leaf
resistance (conductance) to CO2 and water vapour transport, determining
the efficiency in the use of water. The ratio of stomata density
in the adaxial/abaxial leaf surfaces also has been registered
in various species. This information has been used by Willmer
(1985) and Lüttge et al. (1993) for to classify the leaves
of the plants as: amphistomatic (present their stomata in both
surfaces, but generally they are more numerous in the abaxial
surface; as in the majority of herbaceous plants ); hypostomatic
(stomata are only on the abaxial leaf surface of arboreal species;
epistomatic (stomata are only on the adaxial surface; it is presented
by aquatic plants with floating leaves). In typical plants of
L. glaber has been determined that the stomata are predominantly
on the adaxial surface (Arambarri and Colares, 1993).The objective
of this experience was to analyze comparatively the density, dimensions
and the distribution adaxial/abaxial of the stomata of two contrasting
phenotypes highly differentiated in a L. glaber population.
Materials and methods
It was analyzed a typic phenotype (TP) and a phenotype highly
differentiated (DP), found in two successive generations of a
population in process of selection. Plants of both types were
cloned by stem cutting and were cultivated in pots with homogeneous
ground, in natural conditions. A plant of each type was used for
this study.
The leaves were obtained of the middle sector of branches of each
plant. The epidermis was removed from the third middle of the
central leaflet of fresh leaves by the peeling technique. The
adaxial or upper epidermis (UE) and abaxial or lower epidermis
(LE) were extracted from the same sector but of different leaves.
The epidermal samples were mounted in 90% glycerine. The observations
of both epidermic samples were fulfilled with a Leitz microscope
equipped with a lucid camera. Stomata number was register in 50
samples of each epidermis of different leaves. Stomata width and
length were measured in 10 stomata from each sample.
The evaluated stomata characters on both epidermis were: density
(number . cm-2), width and length (µm), the ratio length
/ width and the density ratio UE /LE. Due to the fact that UE
and LE not belonged to the same leaf, the analysis of the density
ratio UE /LE was on four whole pairs at random combined of the
n=50 stomata density data determined on UE and LE.
Data of each character were analyzed statistically and it was
applied the "t" test to validate the null hypothesis
(H0): DP is not different of TP. Besides were determined
the coefficients of single correlation among the characters.
Results and discussion
Table 1 indicates that were found significant differences (t test,
P < 0,01) among DP and TP for the characters: stomata density
on UE and LE, length of the stomata in UE and the ratio width
/length of the stomata in UE.
The stomata density and the stomata size found in both epidermal
surfaces of TP was very approaching to those that had been communicated
by Arambarri and Colares (1993). The DP showed lower stomata density
on both epidermis and stomata on UE longer than the TP plant.
This "dilution" of stomata density of DP has been apparently
balanced by the increasing size, in length of individual stomata,
but it was only on the upper epidermis. In addition to this, similar
changes in stomata characters has been associated with a increase
in the ploidy level (Willmer, 1983).
The variation coefficient indicated that was a wide variation
among the analyzed samples for the stomata density on UE and LE
surfaces, especially in the case of DP. By the contrary, the coefficient
of variation was low for the width and length of the stomata,
especially in the case of DP. These results point out that the
stomata size was more constant character than stomata density
and that this pattern to become more accentuated in DP than TP.
On the other hand, the stomata density ratio UE /LE, the Table
2 shows that the analysis based on random combinations UE-LE density
data denote significant differences among DP and TP (test of "t",
P < 0,01). In L. glaber has been determined that the
leaves present greater stomatal number in the upper epidermis
(Arambarri and Colares, 1993). This sort of distribution adaxial/abaxial
of stomata was confirmed in this experience and more over it was
found that in the "new" (DP) phenotype was significantly
more remarkable (Table 2). Stomata distribution on adaxial/abaxial
epidermis was related with the loss of water from leaves that
is greater from the stomata of adaxial surface (Robins et al ,
1965). According this interpretation the DP plants presents a
ratio that would be favorable to a greater loss of water than
TP plants.
It was determined by the analysis of single correlation that in
TP the analyzed characters varied in independent form (P >
0,05), while in DP only was significant the correlation width
vs. length of the LE stomata, (r=0,48, P=0,0003).
Results indicate that the phenotype "new" (DP) present
differences from the normal (TP) in the stomata density, stomata
length on the UE and density ratio UE /LE. The precedents on the
origin of the evaluated materials and the uniformity of the environment
conditions during their development permit to suppose that the
registered differences could be genetics. This will be studied
in future experiences.
Acknowledgments
The authors wish to express their appreciation to Prof. Ana María
Arambarri, Area de Botánica, for her assistance.
References
Arambarri AM and M Colares, 1993 L. corniculatus L. and L. tenuis Waldst. et Kit (Leguminosae) anatomy of the leaf. Lotus Newsletter, 24: 38-39.
Tichá I, 1985 Ontogeny of leaf morphology and anatomy. In: Photosynthesis during leaf development, De. Zdenek Sestak. 16-50.
Lüttge U., M. Kluge and G. Bauer, 1993. Botánica. McGraw Hill/Interamericana de España, Madrid. 573 pp.
Willmer C M, 1983. Stamata. Longman Group Limited. London. 192 pp.
Robbins WW, TE Weier and CR Stocking, 1965. Transpiration, conduction
and absortion. In: Botany. An introduction to plant science. John
Wiley & Sons, Inc., third edition. 167-181.
| Table 1. Means and variation parameters of the foliar stomata characters in two contrastant phenotypes of Lotus glaber (TP= typical phenotype and DP= differentiated phenotype). The characters were determined on upper epidermis (UE) and on lower epidermis (LE). n=50 | ||||
| Stomata density on UE (no. cm-2) | TP: 20,720.1**
DP: 16,845.1 | 5,073.97 | 5,284-28,861 | 30.12 |
| Stomata density on LE (no. cm-2) | TP: 15,698,8** DP: 8,072.74 | 3,996.36 | 2,845-19,105 | 40.83 |
| Stomata length on UE (µm) | TP: 22.6** DP: 25.72 | 1.49 | 20.5-29 | 5.78 |
| Stomata width on UE (µm) | TP: 20.01 n.s. DP: 20.05 | 0,31 | 19.5-21 | 1.53 |
| Width/length ratio on UE | TP: 0.89** DP: 0.77 | 0.04 | 0.69-0.91 | 4.94 |
| Stomata length on LE | TP: 23.9 n.s. DP: 24.02 | 1.38 | 21.5-28.5 | 5.76 |
| Stomata width on LE | TP: 20.3 n.s. DP: 19.7 | 0.61 | 17-20.5 | 3.07 |
| Width/length ratio on LE | TP: 0.86 n.s DP: 0.82 | 0.04 | 0.7-0.93 | 4.49 |
(**): indicated significant differences (t test, P < 0,01),
between the means of TP and DP for each character.
(n.s.): differences are not significant.
| Table 2. Distribution adaxial/abaxial of stomata determined by density ratio (stomata density on upper epidermis/stomata density on lower epidermis). (A), (B), (C) and (D) are whole of random combinations (n=50) of stomata density on upper epidermis and lower epidermis, obtained of different leaflets. TP and DP are typical and differentiated phenotypes of L. glaber, respectively. | ||||
(X) | coefficient | |||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
(**): difference between XTP and XDP is
significant (t test, P<0.01)
Lotus glaber Mill. (syn. L. tenuis Waldst. et Kit ex Willd). is the only important pasture legume for the Flooding Pampa (Depresión del Río Salado), the most extensive region for calf production in Argentina (7.5 million hect.). The species has perfectly adapted to the unfavorable environmental conditions of this area, to such an extent that during spring and summer it is a dominant species in the natural grasslands that cover the region (Collantes et al. 1988).
Our previous studies in birdsfoot trefoil have demonstrated the dependence of flavonoid composition on developmental stage (Strittmatter et al. 1992, 1994; Wagner et al. 1996). Kaempferol and its glycosides were identified during the whole life cycle of the plant in different organs, whereas free quercetin (Q) and its two glycosides could only be detected in the seeds of L. glaber (Strittmatter et al. 1994; Wagner et al. 1996).
In the present study, the identification of seed flavonoid was
completed including the isoflavones. Their distribution was examined
during germination, as well as in exudates from seeds, in order
to evaluate the role of these flavonoids in response to soil bacteria.
Experimental procedures
Lotus glaber cv. Tresur Chajá, the only registered cultivar in Argentina, was used. Five grams of authentic seeds were extracted with boiling water during 30 min. The aqueous solution was subjected to reduced pressure and the residue redissolved in methanol.
Other 5 g from the same seed lot were washed with a mixture of hydrogen peroxide 100 vol. and methanol 1:1 for 7 min. After rinsing in sterile water, seeds were transferred to a refrigerator (4C) in 50 ml of sterile water during 72 h. This water was evaporated and the residue redissolved in methanol.
The imbibed seeds were then transferred onto pre-wetted filter paper in sterile Petri dishes. Seeds were then germinated at 25C under fluorescent light with a 16 h photoperiod during 4 days. The exudates from germinated seeds were collected by extracting the filter papers with 50 ml of distilled water. This aqueous solution was evaporated under reduced pressure and the residue redissolved in methanol. The germinated seeds were submitted to the same extraction procedure as described previously for dry seeds.
The isolation and purification of flavonoids was achieved by descending chromatography using HOAc 15% on 3 MM Whatman paper. Each band was eluted with methanol and chromatographied again in BAW (n butanol-HOAc-H2O, 4:1:5, upper phase). The obtained compounds were eluted in methanol and analysed using standard procedures (Mabry, Markham and Thomas, 1970; Markham, 1982 and Waterman and Mole, 1994).
The experiments were performed twice with similar results.
Results
When dry seeds of L. glaber were tested for their flavonoid
composition, not only kaempferol (K), quercetin (Q), quercetin-3-O-galactoside
(QGa) and quercetin-3-O-glucoside (QGl) were identified (Wagner
et al. 1996); a kaempferol-3-O-triglucosyl-7-O-rhamnoside (KSR)
and a possibly polysubstituted isoflavone (I) were also detected.
The structure of this isoflavone will be confirmed with MS techniques.
These latter metabolites (KSR and I) are extremely soluble in
water as shown by their high Rf values (0.77 and 0.95, respectively)
(Table 1).
| Table 1: Rf values of the different compounds | |
| quercetin-3-O-glucoside (QGl) | |
| quercetin-3-O-galactoside (QGa) | |
| kaempferol-3-O-sophoroside-7-O-rhamnoside (KSR) | |
| isoflavone (I) | |
The results indicate that when relative concentrations of each flavonoid were compared (Table 2), dry seeds (control) and the filter papers showed the highest concentration of all compounds analysed. Aglycones were released during germination, wheras it was possible to detect KSR and I in the water used for the imbibition of the seeds, because of their high solubility.
After a period of 4 days all flavonoids remained in the germinated
seeds in their lowest relative concentration (Table 2).
| Table 2: Relative concentrations of flavonoids in Lotus glaber seeds during the first stages of germination | ||||
| (+ ) traces; + presence; ++ abundance; +++ high abundance | ||||
Discussion
Analysis of the flavonoids released during imbibition and germination of L. glaber seeds confirmed our previous results (Wagner et al. 1996) that Q and its glycosides are the dominant flavonoids in the seeds.
These results agree with Hartwig et al. (1991) and Tsai and Phillips (1991), who detected that nearly half (46%) of the flavonoids fraction released from intact alfalfa seeds consisted of Q or its derivatives.
The presence of an isoflavone in dry seeds of L. glaber is also noteworthy. Bonde et al. (1973) and Ingham (1977) reported the isolation of the two isoflavans sativan and vestitol in leaves of L. corniculatus, a closely related species to L. glaber, but in response to inoculations with fungi. Flavonols and isoflavones released from L. glaber seeds were also identified in dry seeds, and thus, they would not function as phytoalexins; they must have been synthesized previously.
It remains to be determined which seed tissue is the source of the mentioned flavonoids; alfalfa seeds most apparently store the flavonoids in the seed coat (Hartwig and Phillips, 1991), whereas in soybean the amounts of isoflavones were much larger in the cotyledons than in the roots or hypocotyls (Suganuma and Takaki, 1992).
Data from this study suggest the following preliminary model of how flavonoids diffuse from seeds during the initial stages of germination. Seeds release the isoflavone and KSR during imbibition into aqueous solution as well as Q glycosides. The aglycones, which are less soluble in water than glycosides, diffuse away from the already germinating seed as revealed the filter paper (Table 2).
Although it could be questionable to extrapolate directly the
results from this experiment to the soil environment, the mentioned
flavonoids should certainly affect soil microorganisms.
References
Bonde, M.R.; Millar, R.L. and Inham, J.L. 1973. Phytochemistry
12: 2957-2959.
Collantes, M.B.; Kade, M.; Miaczynski, C. and Santanatoglia, O. 1988. Studia Oecologica V: 77-93.
Hartwig, V.A.; Joseph, C.M. and Phillips, D.A. 1991. Plant Physiol. 95: 797-803.
Ingham, J.L. 1977. Phytochemistry 16: 1279-1282.
Mabry, T.J., K.R. Markham and M.B. Thomas. 1970.The Systematic Identification of the Flavonoids, Springer-Verlag, Berlin, New York. pp. 1-175.
Markham, K.R. 1982."Techniques of Flavonoid Identification, Academic Press ed. pp. 1-113.
Strittmatter C.D., Wagner M.L., Kade M. and Gurni A.A. 1992. Bioch. Syst. and Ecol. 20 (7): 685-687.
Strittmatter C.D., Wagner M.L., Kade M., Rivero M., Ricco R.A. and Gurni A.A .1994. Proceedings of The First International Lotus Symposium pp. 199-202.
Suganuma, N. and Takaki,M. 1993. Soil Sci. Plant Nutr. 39 (4): 661-667.
Tsai, S.M. and Phillips, D.A. 1991. Appl. Environ. Microbiol. 57 (5): 1485-1488.
Wagner M.L., Strittmatter C.D., Kade M., Rivero M., Ricco R.A. and Gurni A.A. 1996. YTON 58(1/2): 141-146.
Waterman, P.G. and S. Mole. 1994. Analysis of Phenolic Plant Metabolites,
Blackwell Scientific Publications pp. 1-238.
Flooding effects on the reproduction of Lotus glaber Mill.
and Lotus corniculatus L. were studied under experimental
conditions. The hypothesis that, the effects of flooding on the
reproduction differ with species and plant age, was tested.
Flooding were carried out in winter (42 days flooding), spring
(49 days) and summer (17 days),in pots under field conditions.
Spring flooding was applied to young (133 days) and old (208 days)
plants. Winter flooding did not affect weight and number of fruits
and seeds per plant. Reproductive characteristics in plants of
different age and treatment of the same species were not affected
by spring flooding. Lotus glaber produced more fruits and
seeds than Lotus corniculatus in the spring flooding.
Indeterminate reproduction and higher reproductive effort of young
plants, determined that reproductive traits for each species had
no significant differences between treatments and plant age. Summer
flooding (17 days) promoted both flower and fruit abortion and
a plant mortality of 100 % in L. corniculatus and 50 %
in L. glaber.
Lotus glaber (L.g.) and Lotus corniculatus (L.c.)
were introduced as forage plants in the Flooding Pampa around
50 years ago. While L.g. has naturally colonized the frequently
flooded habitats. L.c. has not shown the same expansion.
In this paper we studied the tolerance to flooding of seeds of
both species. The seeds were flooded during 7 weeks, in controlled
conditions of temperature and light, and samples were taken at
increasing time intervals. Germination percentage (G.P.) of the
seeds was taken as a measure of tolerance to flooding and it was
found that although G.P. decreased with flooding time in both
species, the soft seeds of L.c. lost viability earlier
than those of L.g. With 49 days of flooding, hard seeds
were the only ones that maintained the G.P. and were more frequent
in L.g. (approximately 50 % in L.g. and 6 % in L.c.,
in 5 months old seed). These characteristics probably play an
important role in the capacity of L.g. of colonizing habitats
that are periodically flooded.
Ecología Austral Vol.5, No 2: 157-163, 1995.
INTRODUCTION
The Salado River Basin is an extense area in Buenos Aires province (Argentina) dedicated to beef and dairy cattle production, which is mainly sustained on a grazing system based on native grasslands with a minor portion of cultivated pastures. Therefore, proven the extensive conditions of cattle production in the area, nitrogen contents of the forage biomass is a critical point determining yield for the process. Any future intensification in animal production within a pasture based system will demand an increase in the amount and the quality of forage supply. In this way, great amounts of nitrogen should be incorporated to the plant-soil system (Simpson and Stobbs, 1981). Basically, this can be achieved by periodical applications of nitrogen-containing fertilizers or, alternatively, through the symbiotic fixation of atmospheric nitrogen.
Legumes associate in a symbiotic way with bacteria belonging to the genus Rhizobium, thus producing root nodules where the nitrogen fixation process occurs. Recent agronomic studies about Lotus species cultivated in the introduction garden of the Instituto Tecnológico de Chascomús (INTECH), project L. pedunculatus and L. corniculatus var. hirsutus by their good adaptability to local conditions (Remis et al, 1996). The former is a commercial forage and the latter is a non commercial botanical variety. Both of them have still not been tested nor cultivated in the region. Nutritional evaluations done by our group (Locatelli et al., this issue) suggest that this two species might substantially improve the quality of pastures present in the zone by increasing their protein content.
Condensed tannins are known to be present in Lotus species and their compositions usually differ between them (Pankhurst and Jones, 1979; Pankhurst et al., 1987). These compounds could affect nodulation of such legumes and indirectly diminish plant persistence and quality, particularly in low fertile and poorly drained soils. Pankhurst and Jones (1979) found that delphinidin rich tannins accumulated in roots and ineffective nodules of L. pedunculatus. They suggested that such ineffectiveness could be due to the sensitivity of Rhizobium strains located in the nodules to those compounds. L. corniculatus var. hirsutus roots also contain a high level of delphinidin rich tannins, but lower than roots of L. pedunculatus plants. On the contrary, condensed tannins present in L. glaber do not contain delphinidin in their structure (Pankhurst and Jones, 1979; Pankhurst et al., 1987).
R. loti strains commonly found in soils of the Salado River
Basin are able to form nodules in L. glaber roots. However,
no data concerning the capacity of these strains to nodulate other
Lotus species are currently available. The aim of the present
work was to determine the ability of an indigenous strain of R.
loti isolated from L. glaber to form effective nodules
in other Lotus species. Data are compared with two additional
strains of R. loti: one of them (NZP 2037) is known to
form effective nodules in roots of both Lotus species used
in this study, while the other (NZP 2213) forms ineffective nodules
on some species which contain delphinidin rich tannins in their
roots (e.g. L. pedunculatus) (Pankhurst et al., 1987).
MATERIALS AND METHODS
Plant material and culture: Legumes used in this study were L. corniculatus var. hirsutus and L. pedunculatus. Seeds obtained from the introduction garden were surface disinfected with concentrated sulfuric acid for 15 min, thoroughly rinsed with sterile distilled water and then kept in water for 24h. After that, they were placed in culture tubes containing 20 ml of solid Jensen medium (Vincent, 1970) and incubated in a climatized room at 25°C with a photoperiod of 16 h.
Rhizobium loti strains: Strain 1-INTECh was originally isolated from nodules of L. glaber plants naturally growing in the outskirts of the INTECH. Strains NZP 2037 and NZP 2213 from Beltsville Rhizobium Culture Collection were kindly gifted by Dr. Paul Beuselinck, USDA-ARS, University of Missouri, Columbia, MO, USA. Bacteria were cultured in AMA medium (Vincent, 1970), at 28°C with rotatory shaking.
Nodulation assay: Three days after transfer to culture tubes, seedlings were inoculated with 0.1 ml of bacterial culture and incubated in the above stated conditions for a 6 week period. Combinations of each Lotus species and bacterial strain were done, each one consisting of 24 plants. Control plants were inoculated with the same volume of AMA medium.
Nitrogenase activity determination: Nitrogenase activity
of nodules was measured by using the acetylene reduction technique
(Hardy et al., 1968) on the same plants used for the nodulation
assay. Six weeks old plants were placed in 50 ml culture tubes
(8 plants each) and hermetically closed with rubber caps. Each
treatment included three replicate tubes. Air (5 ml) was withdrawn
and replaced by an equivalent volume of acetylene. Tubes were
incubated at 25°C during 2 h, and then 0.5 ml gas samples
were removed and analysed for acetylene and ethylene content using
a Hewlett-Packard 5890-A gas chromatograph fitted with a flame
ionization detector and "Poropak N" in a 1.5 mm x 1.32
m column.
RESULTS
Figure 1 shows whole plants of L. pedunculatus (Fig. 1A)
and L. corniculatus var. hirsutus (Fig. 1B) inoculated
with three different strains of R. loti: the two collection
strains NZP 2213 and NZP 2037, and the indigenous strain 1-INTECh.
L. pedunculatus plants inoculated with strains NZP 2213 and 1-INTECh
had a morphological aspect similar to that of non-inoculated plants
(Fig. 1A). Their aerial parts were scarcely developed and exhibited
chlorotic leaves. On the contrary, L. pedunculatus plants
inoculated with strain NZP 2037 showed a normal development of
aerial parts and no symptoms of chlorosis were detected on leaves.
On the other hand, L. corniculatus var. hirsutus
plants inoculated with all three strains grew more vigorously
than controls (Fig. 1B), although some chlorosis was observed
in leaves of plants inoculated with strain 1-INTECh. Nodules formed
by strain NZP 2037 in both Lotus species looked similar
. They were spherical and pink coloured. Strains NZP 2213 and
1-INTECh also formed this type of nodules in L. corniculatus
var hirsutus plants but in L. pedunculatus
plants they formed pseudonodules.
Figure 1: Nodulation of plantlets of L. pedunculatus (A)
and L. corniculatus var hirsutus (B) by Rhizobium
strains (from left to right : control, 1-INTECh, NZP 2213 and
NZP 2037).
Table 1 shows results obtained when nitrogenase activity was measured in nodules of Lotus plants inoculated with the three different R. loti strains. As shown, strain NZP 2037 was capable of forming effective, nitrogen-fixing (Nod+ fix+) nodules with the two species of Lotus. Strain NZP 2213 formed (Nod+ Fix+) nodules in L. corniculatus var. hirsutus and ineffective (Nod+ Fix-) nodules in L. pedunculatus. Indigenous strain 1-INTECh formed (Nod+ Fix-) nodules in both species, even when the morphology of those formed in L. corniculatus var. hirsutus was very similar to that of effective ones.
| Table 1. Atmospheric nitrogen fixing ability of root nodules of Lotus species inoculated with three different R. loti strains. | ||
| Rhizobium strain | ||
| None | ||
| NZP 2037 | ||
| NZP 2213 | ||
| 1-INTECh | ||
DISCUSSION
The observed ability of the R. loti collection strains NZP 2213 and NZP 2037 to nodulate L. pedunculatus and L. corniculatus var. hirsutus, as well as efectiveness of such nodules is in agreement with results reported by Pankhurst et al. (1987), except for the interaction between NZP 2213 and L. corniculatus var. hirsutus. In our hands, the latter symbiosis association rendered effective nodules (Nod+ fix+), which is in contrast with previous results reported by Pankhurst el al. (1987) showing the formation of ineffective nodules. A possible explanation for this discrepancy could be attributed to physiological changes in L. corniculatus var. hirsutus performed after adaption to soils of our region.
Concerning the inability of the indigenous R. loti strain
1-INTECh to form effective nodules in roots of both Lotus
species studied, it is concluded that Rhizobium strains
capable of forming effective nodules and succesfully compete with
native strains should be obtained to introduce these plant species.
Thus, if future attempts to cultivate L. pedunculatus or
L. corniculatus var. hirsutus are made in the region,
the use of such adequate bacterial strains could greatly contribute
to the improvement of legume forage productivity and quality.
However, it is necessary to point out that these experiments should
be checked by using a greater number of indigenous isolates, to
confirm that the behavior of strain 1-INTECh is representative
of the local R. loti population.
ACKNOWLEDGMENTS
The authors wish to thank M.L. Locatelli for helpful discussion. MJE is a Fellow from Comisión de Investigaciones Científicas (CIC, Bs. As.). RAU and AAI are Members of the Investigator Career from Consejo Nacional de Investigaciones Científicas (CONICET).
REFERENCES.
Hardy, R.W.F.; R.D. Holsten; E.K. Jackson and R.C. Burns (1988) Plant Physiol. 43: 1185-1207.
Pankhurst, C.E. and W.T. Jones (1979) J. Exp. Bot. 30: 1109-1118.
Pankhurst, C.E.; D.H. Hopcroft and W.T. Jones (1987) Can. J. Bot. 65: 2676-2685
Remis, J.L.; O.A.Ruiz; R.A.Ugalde and A.A.Iglesias (1995) Lotus Newsletter 26:17-20
Simpson, J.R. and T.H. Stobbs (1981) In: Grazing Animals (Morley, F.W., ed.). pp. 261-287. Elsevier Scientific Publishing Company, Melbourne.
Vincent, J.M. (1970) A Manual for the Practical Study of Root Nodule Bacteria. Blackwell Scientific Publications, Oxford.
INTRODUCTION
Beef and dairy cattle production in the Salado River Basin is essentially a grazing system mainly based on natural grasslands, with a minor portion of cultivated pastures. Edaphic characteristics: limed and poorly drained soils with severe phosphorus deficiency, medium organic matter levels, high alkalinity and salinity; together with periodic exposition of soils to waterlogged conditions, significantly decrease persistence and yield of common legume species (red clover, alfalfa, white clover) in this region (Mazzanti et al., 1986). A strategy to be developed to solve these problems is the introduction of foreign legume species. In this way, Lotus spp. is an important alternative, after their growing conditions and significant nutritional value. Currently, the genus Lotus has been introduced in the Salado River Basin which counts with L. corniculatus and L. glaber (already naturalized) species. However, at the present time, information about nutritional quality (and its variability throughout the year) of commercial species in the area is scarce, and an exhaustive analysis on the productive performance of Lotus in the region is far from complete.
In grazing systems (preferentially extensive) animal production will be highly influenced by nutritional variability of forage offer along the year. Therefore, it is relevant to know (besides biomass production) the nutritional attributes (protein, energy, etc.) and the efficiency by which ruminants profit different legume forage species. After this information, it is possible to design different utilization and agronomic management strategies to obtain a maximum yield from a specific forage material. It has been reported (McGraw et al., 1989) the relevance of an early evaluation of quality parameters in introduction trials of unknown species, in order to identify desirable or undesirable characteristics and thus to postulate rationale strategies for the improvement of forage quality.
Last year, we reported studies carried out at Instituto Tecnológico
de Chascomús (INTECH) concerning green and dry matter production
for different Lotus spp. growing at an introduction garden
located in the Salado River Basin region (Remis et al., 1995).
The present study completes that previous evaluation by analysis
of chemical and biological parameters determining the quality
of the different plant species.
MATERIALS AND METHODS
Aerial biomass (whole plant) of the different Lotus entries (perennial species) was sampled from small plots of the introduction garden during years 1994 and 1995. According to seasonal periods and plant species, these samples included leaves, stems, flowers and/or fruits. Distribution in the different seasonal periods was made by considering the time of sample collection as follows: i) Fall-winter: from late March to early August, ii) Spring: from mid October to mid November, and iii) Summer: from late December to mid February. Samples were oven-dried at 60°C until constant weight to determinate dry matter (DM) content (data expressed as % of the aerial biomass), and then milled to 1 mm by using a Wiley-type mill.
Crude protein (CP) was estimated in the samples by total nitrogen
determination after sulfuric acid digestion, distillation and
titration by the Kjeldahl method (N x 6.25). Neutral detergent
fiber (NDF) was determined according to Goering and Van Soest
(1970). The enzymatic pepsin-cellulase method (Donofer et al.,
1963) was use to measure DM in vitro digestibility (DMIVD) of
the samples. CP, NDF and DMIVD are expressed as % of the DM.
RESULTS AND DISCUSSION
Table 1 shows quality parameters determined for periods of spring and summer in different Lotus spp. grown at the introduction garden in INTECH. Data corresponding to Medicago sativa and Trifolium pratense are included to establish a comparison with two commonly used forage species. As shown (Table 1) besides L. glaber and L. corniculatus (the two commercial species already used in the region) other forage materials exhibited relatively low NDF levels, as well as CP and DMIVD values higher than the mean found for the different Lotus spp. analyzed. In this way, L. corniculatus var. hirsutus showed a good pattern of quality parameters, thus reinforcing the promising data previously obtained with this species (Remis et al., 1995). Table 1 also shows that the hybrid L. corniculatus x L. pedunculatus exhibited high values of CP and DMIVD during the spring, whereas similar results are observed for L. parviflorus during the summer peirod. Concerning L. rectus, Table 1 shows that this species exhibited low parameter values estimating quality. However, it needs to be considered that L. rectus was the only arbustive species in the introduction garden, and that the data could be masked by a significant proportion of lignified stems in the samples. Periodic defoliations of aerial biomass could reverse the low leaf to stem ratio found in our samples and renders a more actual picture of the nutritive value of L. rectus when utilized by ruminants.
Results obtained with L. corniculatus and L. pedunculatus are in agreement with those reported by Carámbula et al. (1994) for acid, poorly drained, and phosphorus depleted soils in the East of Uruguay. Concerning the latter species, Table 1 shows relatively high levels of CP content but low DMIVD values. It is necessary to point out that the methodology we applied in this study determines only ruminal digestibility. Since L. pedunculatus species possesses high condensed tannin levels (5-10% of the DM) (Lowther et al., 1987; Roberts and Beuselinck, 1992), it is feasible that these compounds decrease DM digestibility at rumen (Chiquette et al., 1989; Waghorn et al., 1994), although DM digestion of this species at hind gut could equilibrate the global process (Barry et al., 1986).
As shown in Figure 1, quality parameters for L. corniculatus
var. hirsutus are maintained relatively high along
the year, being the variations comparable with those observed
in L. corniculatus and L. glaber. It has been reported
(Forde and de Lautour, 1978; Kelman and Tanner, 1990) that L.
corniculatus var. hirsutus contents higher amounts
of condensed tannins (3.5-7% of the DM) than L. corniculatus
and L. glaber, which determines a nutritional advantage
for the former species. Taking into account these results, and
considering the reseed capacity and high yields of DM found for
L. corniculatus var. hirsutus at the introduction
garden (Remis et al., 1995), together with the high quality nutritional
characteristics reported herein; it is concluded that this species
is potentially important for the region. Future incorporation
of L. corniculatus var hirsutus into forage mixed
pastures or through interseed on natural grasslands, as well as
its use to obtain hybrid species possessing higher productivity
and quality are important alternatives to be developed for the
improvement of pastures in the region. Works in our Institute
are on the way, looking for technological tools to reach an increase
of productivity in the Salado River Basin.
ACKNOWLEDGMENTS
The authors are greatly indebted to D.F. Gómez Casati and
G.A. Polenta for helpful suggestions on the experimental procedures.
AAI is a Member of the Investigator Career from CONICET.
REFERENCES
Barry, T.N., Manley, T.R. and Duncan, S.J. 1986. The role of condensed tannins in the nutritional value of Lotus pedunculatus for sheep. 4. Sites of carbohydrates and protein digestion as influenced by dietary reactive tannin concentration. British J. Nutr. 55:123-137.
Carámbula, M., Ayala, W. and Carriquiry, E. 1994. Lotus pedunculatus. Adelantos sobre una forrajera que promete. Serie Técnica Nº 45. INIA, Uruguay.
Chiquette, J., Cheng, K.J., Rode, L.M. and Milligan, L.P. 1989. Effect of tannin content in the two isosynthetic strains of birdsfoot trefoil (Lotus corniculatus L.) on feed, digestibility and rumen fluid composition in sheep. Can. J. Anim. Sci. 69:1031-1039.
Donefer, E. Niemann, P.J., Crampton, E.W. and Lloyd, L.E. 1963. Dry matter disappearance by enzyme and aqueous solutions to predict the nutritive value of forages. J. Dairy Sci. 46:965-970.
Forde, M.B. and de Latour, G. 1978. Plant introduction trials. Classification of Lotus introductions. N.Z. J. Exptl. Agr. 6:293-7.
Goering, H.K. and Van Soest, P.J. 1970. Forage fiber analysis (apparatus, reagents, procedures and some applications). Agric. Handbook 379. USDA.
Kelman, W.M. and Tanner, G.J. 1990. Foliar condensed tannin levels in Lotus species growing on limed and unlimed soils in South-Eastern Australia. Proc. N.Z. Grassl. Assoc. 52:51-54.
Lowther, W.L., Manley, T.R. and Barry, T.N. 1987. Condensed tannin concentrations in Lotus pedunculatus cultivars grown under low soil fertility conditions. N.Z. J. Agric. Res. 30:23-25.
Mazzanti, A., Darwich, N.A., Cheppi, C. and Sarlangue, H. 1986. Persistencia de pasturas cultivadas en zonas ganaderas de la Pcia. de Buenos Aires. Rev. Arg. Prod. Anim. 6 (Sup. 1):65.
McGraw, R.L., Beuselinck, P.R. and Marten, G.C. 1989. Agronomic and forage quality attributes of diverse entries of birdsfoot trefoil. Crop Sci. 29:1160-1164.
Remis, J.L., Ruíz, O.A., Ugalde, R.A. and Iglesias, A.A. 1995. Evaluation of Lotus spp. growth in the Salado River Basin. Lotus Newslett. 26:17-20.
Roberts, C.A. and Beuselinck, P.R. 1992. Condensed tannins in Lotus species. Lotus Newslett. 23:41.
Waghorn, G.C., Shelton, I.D. and McNabb, W.C. 1994. Effects of condensed tannins in Lotus pedunculatus on its nutritive value for sheep. 1. Non-nitrogenous aspects. J. Agric. Sci. 123:99-107.
| Table 1: Nutritive parameters (%) in whole plants of Lotus spp. during spring-summer periods. | ||||||||
| Species | ||||||||
| M. sativa1 | ||||||||
| T. pratense1 | ||||||||
| L. glaber | ||||||||
| L. corniculatus | ||||||||
| L. corniculatus var. hirsutus | ||||||||
| L. corniculatus var. alpinus | ||||||||
| L. corniculatus x pedunculatus | ||||||||
| L. filicaulis | ||||||||
| L. parviflorus | ||||||||
| L. pedunculatus | ||||||||
| L. rectus | ||||||||
| MEAN | ||||||||
| DEVIATION | ||||||||
1 Data from Fernández and Galli. 1993 (INTA Rafaela, Argentina) corresponding to studies carried out in the humid pampa region (Argentina).
Figure 1: Seasonal variation for quality parameters obtained from whole plants of L. glaber (continuous lines), L. corniculatus (big dashes) and L. corniculatus var. hirsutus (small dashes). Spg = spring; Sum = summer; and F/W = fall/winter.
Ethephon (2-chloroalkylphosphonic acid) is regarded as "liquid"
ethylene and is probably widely used as plant growth regulator
in agriculture. Ethephon is an ethylene generator. Their breakdown
occurs primarily on the leaf surface and in the aqueous plants
fluids (Abeles et al. 1992). The ethylene acting as a natural
volatile hormone and have an effect on many physiological process.
The objective of this communication was to inform about some abnormalities
registered by the seedlings growth of Lotus glaber, presumably
due to an accidental exposition to exogenous ethephon.
L. glaber seeds were sown in vermiculite contained in a
tray. They were cultivated in a greenhouse with a supply of nitrofoska
2 (BASF) 3gr/l. The substrate was maintained at the water saturation
point. From their sowing this tray remained accidentally exposed
to an ethephon sprinkled (10-4 a 10-5 M)
applied on another trial.
After the seedling emergence it was observed a notorius alteration
in the uniformity size of the seedlings aerial part. Among the
fourth and fifth weeks the seedlings were removed from the tray
and it were evaluated the roots and the aerial components.
The seedling abnormalities observed were: The roots of the most
seedlings showed some alterations in their morphology and size,
inhibition of roots elongation coupled with lateral swelling ,
hypertrophyes, be bent into curls and a negative gravitropism
in lateral roots. The more important seedling abnormalities are
shown in the figure 1 (a). Seedlings with their roots affected
and also normal seedlings were registered, (n=114). The frequency
of seedlings affected and unaffected was 73.68% and 26.32%, respectively.
Figure 1. (a) Seedling abnormalities: small size of aerial part,
hypertrophyes and curls in the root system. (b) Recovery of the
abnormal seedlings after fourth weeks cultivated at the open air.
The abnormal plants were cultivated during fourth weeks at the
open air in pots with agricultural ground to evaluate their following
behavior. During the fourth weeks that the plants were cultivated
in the open air it was register that the affected plants were
recovering gradually their normal growth. Immediately to the end
of this period was observed that, from the affected roots had
been originated roots with normal morphology (figure 1 ( b)).
REFERENCES
Abeles FB, PW Morgan and ME Saltveit Jr (1992) Ethylene plant
biology. Academic Press Inc.. New York. 414 pp.
Abstract. The Lotus strigosus var. tomentellus
complex from Lower California and Sonora, Mexico in which "phases"
to denote aberrant forms or intermediates within a species have
been found was studied morphologically. Until present the phases
1 and 2 are knowledge for L. strigosus var. tomentellus
Isely. The specimens of herbarium (MEXU) were examined with a
stereoscopic microscope and the topographic features of the testa
were analyzed by SEM. According to morphological characteristics
found the specimens studied were separated in three groups. The
group 1 correspond to L. strigosus var. tomentellus
"phase 1" Isely. It is characterized by the presence
of peduncled inflorescence with flowers more than 7 mm length,
and the bract 1-2 (-3) leaflets. The groups 2 and 3 agree with
L. strigosus var. tomentellus Isely by the presence
of flowers no more than 6 mm length, subsessiles or shortly peduncled
and bract absent. However, fruit and seed characteristics delimit
two new morphological phases to L. strigosus var. tomentellus
from Lower California and Sonora, Mexico. They are "phase
3" to group 2 with fruit incurved, falcate, and seed with
the hilum superficial, and "phase 4" to group 3 with
fruit distally incurved and seed with the hilum sunken in a lateral
notch.
Key words: Fabaceae; Loteae; Lotus; Lower California;
Mexico; morphology; phases; Sonora.
Introduction
Isely (1981) uses the word "phases" to denote aberrant forms or intermediates within a species. Such "phases" have been found in this study in the L. strigosus var. tomentellus complex from Lower California and Sonora, Mexico.
Lotus strigosus (Nutt.) Greene, L. strigosus var. hirtellus (Greene) Ottley and L. strigosus var. tomentellus (Greene) Isely are distributed in California, Lower California, and Mexico.
The Lotus strigosus group shows a continuous variation in its morphological characteristics. According to Isely (1981), Nuttall's (1838) names Hosackia nudiflora, H. rubella and H. strigosa illustrate local population variance. Greene (1890) examined and subdivided Nuttall's species in the L. strigosus group. He renamed L. tomentellus to one species from Lower California.
Later, Ottley (1923, 1944) distinguished three taxa, namely, L. strigosus, L. strigosus var. hirtellus and L. tomentellus which she based on seed characteristics. She described the seed of L. strigosus, and L. strigosus var. hirtellus as: "cubical, notched at the hilum" and that of L. tomentellus as "globose to oval an occasional one cubical."
Isely (1981) reduced L. tomentellus to a variety of L. strigosus. At the same time he established two phases, both for L. strigosus (phase 1 and 2) and for the var. tomentellus (phase 1 and 2) based on the fact that the phases represent "aberrant forms or intermediates."
This study redefines the characteristics found in specimens of
L. strigosus var. tomentellus from Lower California
and Sonora.
Materials and Methods
The specimens studied were from (MEXU), Herbario Nacional de Mexico,
Instituto de Biologia, Universidad Nacional Autónoma de
Mexico. The acronym for the herbarium is given according to Holmgren
et al. (1990). The morphological characters were examined with
a Wild M 8 stereoscopic microscope equipped with a camera lucid.
The topographic features of the testa were examined from whole
seeds and portions of them by means of a Jeol JSM T100 scanning
electron microscope (SEM). Drawings of the characters were prepared.
Results and Discussion
According to morphological characteristics, the specimens studied have been separated in groups as follows:
Group 1.
LOWER CALIFORNIA. Western base of Cocupah Mts., on shores of Laguna Maguata, C. Epling, M. Darsie, W. M. Stewart and W. M. Robison, s. n. Feb-19-1933 (552731 MEXU).- Loc. Puerto Refugio, Punta Norte de la Isla Angel de la Guarda, Mpio. Ensenada, 029º 33' 00 N lat, 113º 34' 00 W long, Elev. 50 m s. n. m. Pedro Tenorio L. 10849, C. Romero de T., Feb-07-1986. Desierto sarcocaulescente, suelo arenoso-pedregoso (523662 MEXU).
SONORA. Tiburon Island, Ensenada Blanca, vicinity 28º 59'
N lat, 112º 29½' W long, Joe Edmundson; Alexander Russell,
R. S. Felger , R.S.F. 17276, Feb-20-1968. (447029 MEXU).
Group 2.
LOWER CALIFORNIA. Loc. Desierto de Vizcaino, Arroyo San José de Castro, Mpio. Mulejé. Elev. 160 m s. n. m.; Jorge Cancino Hernández 6, Jun-26-1983. Hierba anual de 7 cm . Abundancia regular. Vegetación circundante matorral subinerme, vegetación halófila, en potrero. (354700 MEXU).- Loc. Desierto de Vizcaino, E de Bahía Asunción, Mpio. Mulegé. Jorge Cancino, Carlos Plata, C. 68; Feb-11-1984. Hierba anual escasa, 10 - 15 cm altura. Vegetación primaria de ecotono, duna mat. halófilo; suelo arenoso. (428089 MEXU).- Loc. La Bocana, Mpio. Santa Rosalía, 26º 53' N lat, 113º 44' W long. Elev. 20 m s. n. m. Pedro Tenorio L 12927, C. Romero T. Apr-17-1987. Hierba escasa, flores amarillas. Vegetación de dunas; suelo amarillo arenoso. [(282843 MEXU), both L. strigosus var. tomentellus and L. salsuginosus var. brevivexillus are on the same sheet].
SONORA. Tiburon Island, Ensenada de La Perra; vicinity 28º
47' N lat, 112º 16' long. R. S. Felger, J. Edmundson, N.
Thomas, R. S. F. 17724, Apr-12-1968. (453698 MEXU).
Group 3.
LOWER CALIFORNIA. Loc. San Ignacito, 14 km al SW de Cataviña, por la carr. transpeninsular, Mpio. Ensenada. 29º 47' N lat, 114º 45' W long. Elev. 640 m s. n. m. Pedro Tenorio L. 13110, C. Romero de T. Apr-28-1987. Hierba postrada, abundante, fl. amarilla, fr. inmaduro. Vegetación matorral desértico, primaria; suelo arenoso amarillo. [(155141 MEXU), specimen corresponds to L. strigosus var. tomentellus, the envelope attached contains a mixture of the specimen L. strigosus var. tomentellus with L. salsuginosus var. brevivexillus].
SONORA. On hillsides of volcanic rock 2.5-3 mi N of Sáric,
approx. 31º 07' N lat, 111º 20' W long. Elev. 2900 ft.;
Grady L. Webster 22517, Mar-26-1978. Scrub of mesquite, saguaro,
Cercidium, et al. Postrate, fls. yellow. (305643 MEXU).- Coast
of the Gulf of California near the mouth of the Rio Concepcion,
10.6 mi. NE of El Desemboque on the road toward Caborca. Near
30º 40' N lat, 112º 57' W long. Elev. 100 ft. A. C.
Sanders, M. Dimmitt, G. Montgomery, et al. 3479, Mar-7-1983. Sandy
coastal flats with low dunes; creosote Bush Scrub with Larrea
and Ambrosia dunosa. A fairly common yellow-flowered annual. (358773
MEXU).- Loc. km 71 de la carr. Sonoyta-San Luis Río Colorado.
32º 04' N lat, 113º 34' W long. Alvaro Campos V 4435a,
J. L. Panero, L. I. Cabrera, Feb-28-1992. Hierba 20 cm altura,
fl. blanca, fr. verde, frecuente. Vegetación matorral espinoso
con Opuntia. (578101 MEXU).
Group 2 fruit incurved, falcate and seed with the hilum superficial.
Group 3 fruit distally incurved and seed with the hilum sunken in a lateral notch.
KEY TO "PHASES" OF L. STRIGOSUS VAR. TOMENTELLUS
FROM LOWER CALIFORNIA AND SONORA, MEXICO
Acknowledgments
I express my appreciation to Curators of the Herbario Nacional
de Mexico (MEXU). I also thank Prof. William F. Grant for his
helpful comments on the manuscript, and Rafael Urrejola for technical
assistance using SEM.
References
Greene, E. L. 1890. Enumeration of the North American Loti. Pittonia 2: 133-150.
Holmgren, P. K. , N. H. Holmgren and L. C. Barnett. 1990. Index Herbariorum. P. 1. The Herbaria of the World. [Regnum Veg. 120]. NY Bot. Gard., Bronx.
Isely , D. 1981. Leguminosae of the United States. III. Subfamily Papilionoideae: tribes Sophoreae, Podalyrieae, Loteae. Mem. NY Bot. Gard. 29(3): 124-264.
Nuttall, T., Torrey, J. and A. Gray. 1838. Leguminosae. In: Flora of North America 1: 326. NY.
Ottley, A. M. 1923. A revision of the Californian species of Lotus. Univ. Calif. Publ. Bot. 10: 189-305.
Ottley, A. M. 1944. The American Loti with special consideration
of a proposed new section, Simpeteria. Brittonia 5(2): 81-123.
Crownvetch (Coronilla varia L.) and birdsfoot trefoil (Lotus corniculatus L.) can be used as perennial living mulches in the production of corn (Zea mays L.), soybeans (Glycine max L.) small grains and forages. The primary benefit is the almost total reduction in soil erosion. Other benefits are enhanced productivity through soil conservation, increased soil organic matter and organic nitrogen, improved soil tilth, better footing during spring planting and fall harvesting seasons when it might otherwise be too wet to get into the field. Positive side effects include a reduction in environmental pollution from soil, nutrient and pesticide runoff, recycling of nutrients from deeper in the soil profile and more flexibility in meeting soil erosion criteria, including increasing the amount of corn and soybeans that can be grown on sloping cropland than otherwise would be allowed.
With the recent introduction of imidazolinone resistant (IR) corn and a weed control program based on imazethapyr, it is now possible to establish these legumes in corn without injuring the corn or the legume ground cover. Crownvetch is very slow to establish but when once established it will persist forever with the right management. Birdsfoot trefoil provides quick cover but gradually thins out over a period of years as a result of crownvetch competition and chemical suppression, leaving a predominately crownvetch cover. Corn of any kind can be planted into a one year old stand of birdsfoot trefoil and crownvetch using a recommended rate of rimsulfuron + thifensulfuron (Basis) for weed control with little or no injury to the cover crop or corn. Atrazine at a rate of 0.5 to 0.75 lb/A needs to be tank mixed with Basis to suppress the birdsfoot trefoil so it won't compete with the corn. Generally corn yields have not been suppressed when cover crop suppression is 95 to 98% for the first six weeks after planting. Fortunately crownvetch and to some extent birdsfoot trefoil will recover and provide up to 80% ground cover by fall even after suppression of this magnitude early in the summer.
Birdsfoot trefoil that is one year old and crownvetch that is two or more years old will tolerate 0.5 lb/A of glyphosate applied at about the time dandelion (Taraxacum officinale Weber in Wiggers) is in bloom. This makes it possible to plant Roundup Ready¨ soybeans and use low rates of glyphosate for weed control and crownvetch or birdsfoot trefoil suppression. Roundup Ready¨ soybean yields up to 60 bu/A were obtained when planted into crownvetch in 1996 but yields up to 75 bu/A were obtained where there was no cover crop. It would appear that some refinement of this system may be necessary to prevent soybean yield suppression when planting into a crownvetch or birdsfoot trefoil living mulch.
Small grains and alfalfa have also been planted into crownvetch and grown without a loss in yield and without losing the cover crop. A blanket treatment of glyphosate or paraquat is commonly necessary before planting small grains or alfalfa to suppress the cover crop for the first six weeks of crop growth. Post treatments may be necessary for annual or winter annual weed control. Two herbicides that crownvetch will not tolerate are clopyralid and 2,4-DB but it will tolerate recommended rates of most other small grain or alfalfa herbicides and still be there in sufficient amounts so reseeding is not necessary when rotating back to corn.
The whole program is explained on the web at: Living Mulch
Two species of the genus Lotus are agriculturally important
in Argentina because they are adapted to harsh environmental conditions
marginal for alfalfa production. Lotus corniculatus L.
is the main forage legume in Entre Ríos Province (Vertisol
soils) and L. glaber Mill. has become naturalized along
the Flooding Pampa (Molisols and Alfisols).
In spite of the mentioned characteristics practically no breeding
efforts have been performed on these species in Argentina in order
to increase their productivity and persistence.
The basis of any breeding program is to identify and quantify
the species variability (Brown, 1978). To manage this, one possibility
is to characterize isozyme polymorphisms and their distribution
within and among populations (Tanksley and Orton, 1983; Ibañez
et al., 1993). Indeed, isozyme patterns were used to elucidate
the origin of L. corniculatus (Raelson and Grant, 1988).
It was proposed that L. corniculatus is an allotetraploid
being probably L. glaber and/or L. alpinus the maternal
parents of the original hybrid (Ross and Jones, 1985). To our
knowledge, no such studies have been performed in L. glaber.
In this context, preliminary results of isozyme polymorphisms
were investigated, including other enzyme systems, in order to
assess the extent of isozyme variability among and within the
Argentine cultivars of L. glaber and L. corniculatus.
Experimental procedures
Plant material: Commercial seeds of L. glaber
(2n=2x=12) cv. Tresur Chajá and L. corniculatus
(2n=4x=24) cv. El Boyero INTA were subjected to chromosome number
determination and germinated following ISTA Rules (1985). When
seedlings developed the first leaves, they were transferred to
greenhouse conditions (15-25C) during 60 days.
Isozyme electrophoresis: To obtain crude extracts, leaf material was crushed thoroughly in chilled mortars with cold extraction buffer (1:1,5 w:v). Each sample consisted of young leaflets of at least 5 plants for each species. Experiments were replicated twice with similar results. Extracts were absorbed onto 10 x 5 mm wicks of filter paper (Whatman No. 3) and inmediately inserted into slots performed in the starch gel. Electrophoresis was carried out using 11% starch (Sigma) gels prepared with a tris-citrate pH 7.0 buffer for malate dehydrogenase (MDH), 6-phosphogluconate (6-PG) and aspartate aminotranspherase (AAT), tris-citrate/lithium borate pH 8.3 buffer for esterase (EST) and diaphorase (DIA) and histidine/citric acid pH 5.7 buffer for acid phosphatase (ACP). These methods and staining procedures to resolve isozymes are described elsewhere ( Scandalios and Sorensen, 1977).
Gels were incubated at 37C for one hour, in the dark; then they
were fixed in methanol 50%.
Results
The enzymes characterized displayed different patterns for each
cultivar analyzed, with the exception of AAT and 6-PG.
There was an apparent monomorphism among and within L. glaber
and L. corniculatus cultivars for these isozymes.
MDH produced different electrophoretic patterns for each
species showing the greatest variability inside the cultivars
evaluated. Lotus glaber exhibited three patterns, which
had two or three bands in different possitions. That pattern composed
of two bands was also found in some L. corniculatus individuals.
L. glaber samples consisted of one or three bands resulting
in four different patterns.
EST showed two isozyme patterns in each species: L.
glaber samples produced a third esterase band not found among
L. corniculatus patterns, but both cultivars shared the
pattern composed of two variable bands.
DIA enzymes were only evaluated in L. glaber and
two different electrophoretic patterns were characterized consisting
of two bands each.
Patterns of the ACP system provided the greatest differentiation
between species. The cathodal region of the ACP gels in both species
showed a common band. However, in the anodal region L. glaber
ACP bands were almost always faster than L. corniculatus
bands.
Discussion
Differences in electrophoretic patterns of isozymes for cv. Tresur
Chajá (L. glaber) and cv. El Boyero INTA (L. corniculatus)
were detected between and among cultivars. MDH, EST and ACP systems
showed some same patterns. Such a finding may be related to the
presumed hybrid ancestry of L. corniculatus. Ross and Jones (1985)
suggested that either L. alpinus and/or L. glaber could
be the maternal parent of the original hybrid.
Further studies would confirm if ACP system can be used effectively
to differentiate one cultivar from another. The fast band for
L. glaber pattern showed a higher mobility than the same band
for L. corniculatus. This difference was not observed to
be constant, but it is evident from this survey that its frequency
is high. It is clear that these results need to be confirmed with
a larger set of individuals, and perhaps, with small refinements
of the procedure. Besides, Raelson and Grant (1988) did not examined
ACP system in their review concerning the origin of L. corniculatus.
Electrophoretic analysis, which can be also performed on ungerminated
seeds, would resolve questions of seed identification. L. glaber
and L. corniculatus seeds are very similar, therefore
a relatively rapid and accurate method of discriminartion, as
well as the flavonol analysis based on a chromatographic procedure
(Kade et al., 1997), would facilitate classification of seed samples.
References
Brown, A.H.D. 1978. Theor Appl Genet, 52: 145-157.
Ibañez, M.A., Di Renzo, M.A. and M.M. Proverene.
1993. Scientia Horticulturae 53: 281-288.
International Rules for Seed Testing. Rules 1985. 1985.
Seed Sci. and Technol. 13: 299-355.
Kade, M., Wagner, M.L., Strittmatter, C.D., Ricco, R.A. and
A.A.Gurni. 1997. Seed Sci. and Technol.. (in press).
Raelson, J.V. and W.F. Grant. 1988. Theor Appl Genet
76:267-276.
Ross, M.D. and W.T. Jones. 1985. Theor Appl
Genet 71: 284-285.
Scandalios, J.G. and J.C. Sorensen. 1977. 1. Isozymes
in Plant Tissue Culture. In: Plant Cell, Tissue and Organ Culture.
Chapter VII, pp. 719. Ed. by J. Reinert and P.S. Bajaj. Springer
Verlag.
Tanksley, S.D. and T.J. Orton. 1983. Isozymes in
Plant Genetics and Breeding. Part A, B. Elsevier, Amsterdam.
Test and Trial Phase (1998-1999)
Introduction
Subject to ratification by the XVI International Botanical
Congress (St Louis, 1999) of a rule already included in the International
code of botanical nomenclature (Art. 32.1-2 of the Tokyo
Code), new names of plants and fungi will have to be registered
in order to be validly published after the 1st of January
2000. To demonstrate feasibility of a registration system, the
International Association for Plant Taxonomy (IAPT) undertakes
a trial of registration, on a non-mandatory basis, for a two-years
period starting 1 January 1998. The co-ordinating centre will
be the Secretariat of IAPT, currently at the Botanic Garden and
Botanical Museum Berlin-Dahlem, Germany. Co-ordination with present
indexing centres for major groups of plants is being sought, in
view of their possible active involvement at the implementation
stage. The International Mycological Institute in Egham, U. K.,
has already accepted to act as associate registration centre for
the whole of fungi, including fossil fungi.
Registration procedure
The co-ordinating registration centre (IAPT Secretariat),
and any associated centre operating under its auspices, will register
and make available all names of new taxa, all new combinations
or rank transfers that are brought to their attention in one of
the following ways:
by being published in an accredited journal or serial;
by being submitted for registration (normally by the author or
one of the authors), either directly or through a national registration
office; or
(for the non-mandatory trial phase only) as a result of scanning
of other published information by the registration centres' own
staff.
Registration by way of publication in accredited journals
or serials
For a journal or serial to be accredited, its publishers must
commit themselves, by a signed agreement with the IAPT, to
point out any nomenclatural novelties in each individual issue
of their journal or serial, either by including a separate index
of novelties or in another suitable, previously agreed way;
submit each individual issue, as soon as published and by the
most rapid way, to a pre-defined registration office or centre.
Accredited journals and serials will be entitled, and even encouraged,
to mention that accreditation on their cover, title page or in
their impressum.
A permanently updated list of accredited journals and serials
is being placed on the World Wide Web (http://www.bgbm.fu-berlin.de/iapt/registration/journals.htm).
This list will be published annually in the journal Taxon.
Registration by way of submission to registration offices
Authors of botanical nomenclatural novelties that do not
appear in an accredited journal or serial (but e.g. in a monograph,
pamphlet, or non-accredited periodical publication) are strongly
encouraged to submit their names for registration - and will be
required to do so once registration becomes mandatory - in the
following way:
all names to be registered are to be listed on an appropriate
registration form, using a separate form for each separate publication;
the form (in triplicate) must be submitted together with two copies
of the publication itself, either to a national registration office
(see below) or, optionally, directly to the appropriate registration
centre. Reprints of articles from books or non-accredited periodicals
are acceptable, provided their source is stated accurately and
in full;
one dated copy of each form will be sent back to the submitting
author in acknowledgement of effected registration.
Registration forms can be obtained free of charge (a) by sending
a request to any registration office or centre, by letter, fax
or e-mail, or (b), preferably, by printing and copying the form
as available on the World Wide Web (http://www.bgbm.fu-berlin.de/iapt/registration/regform.htm).
Registration offices are presently being arranged for in as many
different countries as possible. They will serve (a) as mailboxes
and forwarding agencies for registration submissions and (b) as
national repositories for printed matter in which new names published
locally appear.
A permanently updated address list of all functioning national
registration offices is being placed on the World Wide Web (http://www.bgbm.fu-berlin.de/iapt/registration/offices.htm).
This list will also be published annually in the journal Taxon.
Registration date
The date of registration, as here defined, will be the
date of receipt of the registration submission at any national
registration office or appropriate registration centre. For accredited
journals or serials (and, for the duration of the trial phase,
for publications scanned at the registration centres), it will
be the date of receipt of the publication at the location of the
registration centre (or national office, if so agreed).
For the duration of the trial phase, i.e. as long as registration
is non-mandatory, the date of a name will, just as before, be
the date of effective publication of the printed matter in which
it is validated, irrespective of the date of registration. Nevertheless,
the registration date will be recorded, for the following reasons:
to make clear that the name was published on or before that date,
in cases when the date of effective publication is not specified
in the printed matter;
to assess the time difference between the (effective or stated)
date of the printed matter and that of registration, since it
is envisaged that the date of registration be accepted as the
date of names published on or after 1 January 2000.
It is therefore in the interest of every author to submit nomenclatural
novelties for registration without any delay, and by the most
rapid means available.
Access to registration data
Information on registered names will be made publicly available
as soon as feasible, (a) by placing them on the World Wide Web
without delay in a searchable database (http://www.bgbm.fu-berlin.de/iapt/registration/regdata.htm),
(b) by publishing non-cumulative lists biannually, and (c), hopefully,
by issuing cumulative updates on a CD-ROM-type, fully searchable
data medium at similar intervals.
Registration as a positive step
(comments of Karen L. Wilson, Royal Botanic Gardens, Mrs
Macquaries Road, Sydney, N.S.W. 2000, Australia.]
Registration of nomenclatural novelties seems to me a natural
way to go, heading into the 21st Century.
It will enable us to find quickly what new names have been published,
and to be sure that we have not missed any new name hidden in
the paper mountain of botanical literature that comes out each
year around the globe. This is particularly important for one-off
publications (floras, field guides, etc.), which are notorious
for `hiding' new names.
Some people seem to think that registration implies censorship,
but this is wrong. As in the current Index
kewensis all names will be listed, and without comment
as to status, and as soon as received at one of the registration
centres. My only caution to those looking at the mechanisms for
making registration effective is that they should ensure there
is a large network of registration centres or offices spread evenly
around the world. This is necessary to make it easy to submit
novelties for registration, given the apparently worsening state
of mail services in all areas.
The taxonomy of the genus Lotus is rich in complicated
problems. On the one hand, the boundaries of the genus and its
subdivisions are often discussed. On the other hand, the delimitation
of species and ifraspecific taxa is sometimes doubtful, as for
instance in Lotus corniculatus complex, Lotus creticus
complex, Lotus angustissimus complex, and in a group of
perennial species of subgen. Syrmatium.
In a broad sense, the genus Lotus comprises, according
to different views, from 100 species (Polhill, 1981) to 176 species
(Kirkbride,1994) on all continents except the Antarctic. The majority
of species occur in the Mediterranean region, Macronesia, and
in the western part of North America, especially in California.
Several species are cultivated as forage plants.
J.H. Kirkbride (1994) presented the worldwide Checklist of the
species of Lotus s.l.
The aim of the present database is maintaining data on the taxonomy,
morphology and geography of Lotus species. Taxonomic boundaries
of the genus Lotus are accepted according to J.H. Kirkbride (1994),
i.e. the genus is treated in the wide sense.
FLORIN Information System developed by DataX/FLORIN Inc. was chosen
as a basic software for maintaining Lotus database. The
System allows to store in a database large amounts of information,
keep them in a good order, browse data using queries-by-example,
generate configurable reports, labels and digital maps for herbarium
specimens, and includes other useful possibilities.
The database is maintained by a personal FLORIN version for MS-DOS.
It contains various information, such as morphological descriptions,
bibliographic citations, taxonomic notes for taxa of different
ranks, and also data on type material and herbarium specimens.
The taxonomic part of the database is being regularly transferred
to Unix platform, and the current version of it is available in
the Internet (the URL:http://www.florin.ru/florin/db/lotus.htm).
Data on herbarium specimens and maps of distribution areas of
species and ifraspecific taxa exist only in a personal MS-DOS
version of the Database.
On the first step of database compilation nomenclatural data were
included. The latest version of the database (November 1997) contains
all specific names published in the genus Lotus since 1753
(507 names).The first citation of each name is available. 193
species of Lotus are accepted and attached to sections
and subgenera according to our point of view. 34 names are included
in database as incertae sedis. The remaining 286 names
are treated as synonyms.
On the second step we plan to insert in the database the types
of all taxa. At the present time, 158 types of species and ifraspecific
taxa are included. Now the database also contains about 100 morphological
descriptions and 350 citations of herbarium specimens (with geographical
coordinates for the majority of them).
References
Kirkbride, J. H., Jr., 1994. - Taxonomic Circumscription of
the Genus Lotus Linnaeus (Fabaceae, Loteae), Its Tribal
Position, and Its Species, pp. 11-15, in Proc. 1 Intern. Lotus
Symposium. St.Louis.
Polhill, R. M., 1981. - Loteae DC., Coronilleae (Adans.) Boiss.,
pp.371-375, in R. M. Polhill & P. H. Raven (eds.) Proc. Intern.Legume
Conf., Kew, 24-29 July 1978. 2. Advances in Legume Systematics
1. Kew.
Seed pod shattering in the genus Lotus (Fabaceae): a
synthesis of diverse evidence. Grant, W. F. Canadian Journal
of Plant Science 76 (3): p.447-456. 1996.
Birdsfoot trefoil (Lotus corniculatus L.) is a perennial
dehiscent species with an indeterminate growth habit. Pod shattering
(shedding) has been a major problem, seed loss was high due to
continuous flowering and time of pod maturity. The anatomy of
the pod plays a role in pod shattering. A change in the orientation
of pericarp cells, unequal swelling and shrinkage occurs, and
a lower lignification of the mesocarp were considered major causes
of shattering. The relative humidity (RH) at the time of harvest
was also a major factor. The critical RH for dehiscence varied
with genotypes between 35 and 49%. There was no correlation for
pod dehiscence between plants grown to maturity under greenhouse
conditions and the same plants grown in the field. Management
practices (time of harvest, clipping early in the season, misting,
mowing and turning the windrow during drying, and desiccants)
were not successful in controlling pod shattering. Shattering
resistance is highly heritable and is considered to be controlled
by more than one gene in Lotus. Breeding to reduce shattering
through recurrent selection was unsuccessful. Attempts to transfer
the indehiscent seed pod trait from distantly related indehiscent
species via interspecific hybridization, diploid bridge species,
amphidiploidy, and backcrossing to birdsfoot trefoil, or similarly
by interspecific somatic hybridization, have shown promise. The
molecular approach has so far not been attempted but since genetic
transformation can be carried out in Lotus, this avenue should
be investigated.
Heterospecific pollen transfer between sympatric species in
a midsuccessional old-field community. McLernon, S. M.; Murphy,
S. D.; Aarssen, L. W. American Journal of Botany 83 (9): p.1168-1174.
1996.
The cumulative (season-long) incidence of heterospecific pollen
transfer (HPT) was examined using nine sympatric species in a
midsuccessional old field in Bedford Township, Ontario, Canada.
Inflorescences were collected weekly during the flowering season,
and the proportion of foreign pollen/stigma was recorded. Flowering
phenologies of sympatric species and ovule and seed counts of
study species were also recorded. Heterospecific pollen was detected
on some stigmas of each species. Medicago sativa (Fabaceae)
received the most foreign pollen; in some cases, all of the grains
on a stigma were heterospecific. Lotus corniculatus (Fabaceae)
received the least amount of foreign pollen; the incidence of
heterospecific pollen was near zero in most cases. The mean and
range of foreign pollen received varied by as much as an order
of magnitude between species. The six species with zygomorphic
flowers, all Fabaceae, received more heterospecific pollen than
the three species with actinomorphic flowers, Potentilla recta,
P. simplex (Rosaceae) and Ranunculus acris (Ranunculaceae).
This probably reflects a bias because the data were analysed on
a cumulative basis and the Fabaceae had longer flowering phenologies.
HPT was not correlated with the species' relative abundance within
the community. Proportion of foreign pollen received varied temporally
within species, and this variation generally was not related to
phenology of any sympatric taxa or the species' own phenology.
Pollen grain diameter was positively related to levels of foreign
pollen received by species. This might be caused by poor adhesion
of large pollen grains to small stigmatic papillae or if generalist
pollinators carrying large amounts of heterospecific pollen visit
the large-grained species and specialists with little foreign
pollen visit the small-grained species. The large proportions
of heterospecific pollen on stigmas of many species indicate that
HPT occurs frequently in the community studied and the implications
may include reduced seed set because of occlusion by foreign grains.
As yet, however, it is unclear how important a factor HPT is in
mediating pollen limitation of reproductive success.
The origin of the Lotus corniculatus (Fabaceae) complex:
a synthesis of diverse evidence. Grant, W. F.; Small, E. Canadian
Journal of Botany 74 (7): p.975-989. 1996.
Although sometimes defined to have diploid populations, L.
corniculatus essentially appears to be tetraploid. Biochemical
and genetic evidence indicates that it is an allotetraploid. Although
about a dozen diploid species have been proposed as ancestral
to L. corniculatus, the evidence points strongly to four.
L. uliginosus uniquely shares a rhizomatous habit, an acyanogenic
factor, and a tannin characteristic with L. corniculatus,
clearly showing an especially close relationship, and reflecting
the possibility that it is one of two direct parental species.
Principal candidates for the second parent include L. alpinus,
L. japonicus and L. tenuis. The phenetic analysis presented
here accords well with the hypothesis that L. corniculatus
arose as a hybrid of L. tenuis and L. uliginosus.
Cytogenetic evidence indicates that L. japonicus is especially
closely related to L. corniculatus. Flower colour in the
hybrids between L. uliginosus and L. tenuis suggest
maternal inheritance and that L. tenuis could have been
the female parent. An evolutionary sequence is suggested in which
L. uliginosus hybridized with L. tenuis, followed
by introgression from L. alpinus and L. japonicus.
Alternatively, a prototype of L. alpinus, L. japonicus and
L. tenuis could have been the female parent of L. corniculatus,
based on evidence from maternal inheritance of flower colour intensity
and interactions of Rhizobium strains.
Some new results on the host range of Macrophomina phaseolina
in Hungary. Kadlicsko, S. Acta Phytopathologica et Entomologica
Hungarica 29 (1-2): p.61-66. 1994.
The importance of M. phaseolina is continually increasing in Hungary.
The host range of the fungus in a small plot inoculation experiment
was studied. The plant species infected by the pathogen were regarded
as susceptible host plants. Among the 37 cultivated plants examined,
28 became diseased. The infected plants included crops sown over
large areas (maize, sunflower, lucerne, sugarbeet and potato)
as well as papilionaceous plants (e.g. lucerne, sainfoin (Onobrychis
viciifolia), red clover (Trifolium pratense) and birdsfoot
trefoil (Lotus corniculatus)). They were highly favourable
for the propagation and survival of the fungus. The proportion
of susceptible weed plants, though somewhat lower (4 out of 10
tested species) is very important because of their wide distribution.
Growth habit of Lotus tenuis shoots and the influence of photosynthetic
photon flux density, sucrose and endogenous levels of gibberellins
A1 and A3. Clua, A.; Bottini, R.; Brocchi, G. N.; Bogino,
J.; Luna, V.; Montaldi, E. R. Physiologia Plantarum 98 (2): p.381-388.
1996. Paper presented at the European Symposium on Photomorphogenesis
in Plants, Sitges, Spain, 9-13 July 1995.
Single-node explants of L. tenuis cv. Tressur-Chaja with
one axillary branch each were incubated in darkness with different
concentrations of sucrose, gibberellin A3 (GA3), B9 (daminozide)
or their combinations, or whole plants were treated with full
sunlight, artificial shade (AS), AS + uniconazole, or AS + cimectacarb
(trinexapac). A high sucrose concentration induced diagravitropic
growth of the axillary branches. GA3 reversed the effect of sucrose,
both in shoot sections and whole plants, inducing orthotropic
growth and diminishing the sucrose levels at the shoot bases.
High irradiance induced a prostrate growth of the shoots. Artificial
shade increased both internode and branch length and induced an
upward curvature of the shoots. This was correlated with a lower
sucrose concentration and increased content of GA1 and GA3. Cimectacarb
and uniconazole reversed the AS effects, although the sucrose
content in the shoots remained low. These results suggest that
gravitropism of L. tenuis shoots under different light
intensities, but similar light quality, is controlled by the levels
of GA1 and GA3 and sucrose.
Legume seeding trials in a forested area of north-central Washington.
Java, B.; Everett, R.; O'Dell, T.; Lambert, S. Tree Planters'
Notes 46 (1): p.19-27. 1995.
Sowing nitrogen-fixing species is a proven silvicultural practice
to increase site nutrient capital, but species' responses are
site specific. Alsike clover (Trifolium hybridum), white
clover (T. repens), black medic (Medicago lupulina),
cicer milkvetch (Astragalus cicer), two varieties of birdsfoot
trefoil (Lotus corniculatus), and Hederma pine lupine (Lupinus
albicaulis), all commercially grown species, were planted
at several altitudes on the Wenatchee National Forest in Washington
state on recently burned disturbed forest sites. After 2 yr, alsike
clover and Hederma pine lupine were the most successful species
on high altitude sites (>1219 m), and black medic and Hederma
pine lupine were the best performers on low altitude sites. Average
total nitrogen inputs from top growth of planted species during
the 1991 growing season were 20 -115 kg/ha. Nitrogen delivered
by atmospheric fixation was 6-40 kg/ha. It is concluded that legumes
can successfully establish in eastern Washington, ameliorating
losses in nutrients after logging and residue treatment. Legumes
increased total nitrogen on these sites and enhanced nutrient
cycling in planted areas.
Cytology of 2N pollen formation and pollen morphology in diploid
Lotus tenuis (Fabaceae). Rim, Y.W., and Beuselinck,
P.R. American Journal of Botany. 83:1057-1062. 1996.
Two genotypes of Lotus tenuis Waldst & Kit. ex Willd.
PI 204882, a diploid (2n = 2x = 12), were identified as producing
2n pollen (maximum = 6%). The objectives of this research were:
(1) to determine the mechanism(s) of 2n pollen formation in the
L. tenuis genotypes and (2) to morphologically describe
n and 2n pollen using light and scanning electron microscopy.
Meiotic studies revealed that 2n pollen resulted from bipolar
spindles during anaphase II of microsporogenesis. The 2n pollen
germinated well, although abnormal pollen tubes were observed.
The genetic constitution of 2n pollen resulting from bipolar spindles
is equivalent to first division restitution (FDR) of meiosis.
Fresh and air-dried pollen samples exhibited differences in size
and shape under light and scanning electron microscopy. The size
of diploid (2n) pollen was larger than that of haploid (1n) pollen.
Normal haploid (1n) pollen was globose-prolate in shape, while
diploid (2n) pollen was tetrahedral in shape.
Use of poultry manure and plant cultivation for the reclamation
of burnt soils. Vazquez, F.J.; Petrikova, V.; Villar, M.C.,
and Carballas, T. In: Biology and fertility of soils. 22:265-271.
1996.
Annual (Pisum sativum L. and Vicia sativa L.) and
perennial (Trifolium repens L. and Lotus corniculatus
L.) leguminous species were grown in pots containing samples from
the ash layers of two Cambisols under Pinus sylvestris
L., which has been affected by high-intensity wildfires 3 and
15 days before the sampling. The gramineous Lolium perenne
L. was cultivated as a second plant after Trifolium and
Lotus harvesting. Three treatments were compared: soils
without fertilization and soils fertilized with two doses of poultry
manure (1 and 2 g total N kg-1 dry soil). The aim of the work
was to study the capacity of the ash layer to sustain vegetation
and the influence of plants and organic manure on the recovery
of vegetation cover, ash layer fixation and soil structure formation
to avoid erosion. The ash samples were able to sustain vegetation
without fertilization. The organic manure increased the yields
of all the plants tested, the lower dose being the optimal for
the first crop whereas the higher dose was beneficial for the
second crop. The annual legumes grew very quickly. The mixture
of Trifolium and Lotus seemed very suitable for
reclamation of soil degraded by wildfires because Trifolium
produced more phytomass than Lotus in the first growing
stages whereas the development of Lotus was higher in the
later growing stages. Ash layer conditions did not inhibit nodulation,
which was, however, stimulated by the organic manure, particularly
in the case of Lotus. Lolium after perennial legumes
was the best plant combination because it produced the highest
phytomass, particularly root phytomass, and thus improved vegetation
cover and ash layer fixation. All the plants tested improved the
formation of soil aggregates, particularly the combination of
perennial legumes and Lolium. However, wet aggregate stability
was higher when plants were grown on soils fertilized with poultry
manure than when plants were cropped on unmanured soils, which
points to the favourable influence of the organic manure on soil
aggregation.
Uptakeof phosphorus from different sources by Lotus pedunculatus
and three genotypes of Trifolium repens. 1. Plant yield
and phosphate efficiency. Trolove, S. N.; Hedley, M. J.; Caradus,
J. R.; Mackay, A. D. Australian Journal of Soil Research. 1996.
V 34:1015-1026.
The breeding of phosphate (P) efficient pastoral legumes could
reduce the amount of fertilizer required on pastoral farms. Lotus
pedunculatus (L. uliginosus) and 3 genotypes of white
clover (Trifolium repens) known to differ in their ability
to respond to added P were grown on unfertilized soil and soil
to which either monocalcium phosphate (MCP) or North Carolina
phosphate rock (NCPR) were added. White clover genotype 8D (a
selection line from Crau) had a greater (P<0.05) internal P
efficiency (shoot DM production per unit plant P) than 1A (a selection
line from Gwenda) or lotus on unfertilized soil, whereas on fertilized
soil, lotus had a significantly higher (P<0.05) internal P
efficiency than 2 of the white clover genotypes on MCP-fertilized
soil (P<0.01) and all 3 white clover genotypes on NCPR-fertilized
soil (P<0.01). Lotus also had a higher (P<0.01) external
P efficiency (total P uptake) than all 3 white clover genotypes
on the 2 fertilized treatments. This was due to a greater root
length, not a greater P uptake per unit length.
Uptake of phosphorus from different sources by Lotus pedunculatus
and three genotypes of Trifolium repens. 2. Forms of phosphate
utilised and acidification of the rhizosphere. Trolove, S.
N.; Hedley, M. J.; Caradus, J. R.; Mackay, A. D. Australian Journal
of Soil Research. 1996. V 34:1027-1040.
To investigate differences in the ability of legumes to acidify
their rhizosphere and extract various forms of P, Lotus pedunculatus
(L. uliginosus) and 3 genotypes of white clover (Trifolium
repens) that varied in their ability to respond to added P
were grown in root study containers with either unfertilized soil,
or soil fertilized with either monocalcium phosphate (MCP) or
North Carolina phosphate rock (NCPR). After 6 weeks of plant growth,
the containers were dismantled and 10 thin soil slices were taken
0-8 mm from the rhizoplane. These slices were fractionated for
various P forms and pH was measured. All 4 legumes, especially
lotus, acidified their rhizosphere. This resulted in negligible
depletion of the small, H2SO4-Pi fraction (Pi, inorganic phosphorus)
of unfertilized and MCP-fertilized soil, but caused direct dissolution
of NCPR. The predominant forms of P depleted in the MCP-fertilized
soil were the resin-Pi and NaOH-Pi forms, whereas in the NCPR
treatment the H2SO4-Pi fraction was depleted. No significant depletion
of any P fraction was observed in the unfertilized soils as plants
were very small and P change in the soil slices was below that
which could be measured using the experimental technique. Suggestions
are made on how the experimental technique could be improved.
Identification of new protein species among 33 different small
GTP-binding proteins encoded by cDNAs from Lotus japonicus,
and expression of corresponding mRNAs in developing root nodules.
Borg, S.; Brandstrup, B.; Jensen, T. J.; Poulsen, C. Plant
Journal. 1997. V 11:237-250.
In this study, 266 cDNA clones were isolated from a cDNA library
constructed from mRNA of three-week-old root nodules of Lotus
japonicus, employing a degenerate oligonucleotide probe that
corresponds to a conserved region of small GTP binding (SMG) proteins.
The clones were sorted into groups by cross hybridization and
3' sequencing, and 33 contigs were sequenced in an orderly fashion.
Twenty-seven complete and six incomplete protein structures were
deduced, which represent three subfamilies of the superfamily
of signal transducing GTP-binding proteins. The 33 proteins are
divided into nine subclasses, of which seven belong to the Ypt/Rab
subfamily, one subclass represents the Rho/Rac subfamily, and
one subclass represents the Ran subfamily of small GTP-binding
proteins. The protein sequences were compared with related proteins
from other plants, from mammals and other species, and discussed
with respect to structure and function in different cellular processes.
It is apparent that the number of genes encoding SMG proteins
in plants must be quite large, since the large number of subclasses
found in other eukaryotes is not fully represented in this analysis.
Transcription patterns through root nodule development were analysed
for 27 of the 33 cDNAs. Differential expression patterns may reflect
whether the coded gene product is of importance for organ development.
Most mRNAs appear to be constitutively expressed; however, a few
unique mRNAs representing the subclasses Rab1, Rab2, Rab5, Rab7
and Rac show elevated levels in root nodules, and certain Rab7,
Rab8 and Rab11 species are enriched in aerial parts of the plant.
This suggests that most small GTPases have housekeeping functions,
whereas a few may be required for specialized activities that
are important for specialized cells.
Cell-specific expression of the promoters of two nonlegume
hemoglobin genes in a transgenic legume, Lotus corniculatus.
Andersson, C. R.; Llewellyn, D. J.; Peacock, W. J.; Dennis,
E. S. Plant Physiology. 1997. V 113:45-57.
The promoters of the haemoglobin genes from the nitrogen-fixing
tree Parasponia andersonii and the related nonnitrogen-fixing
Trema tomentosa both confer beta -glucuronidase reporter gene
expression to the central zone of the nodules of a transgenic
legume, Lotus corniculatus. beta -Glucuronidase expression
was high in the uninfected interstitial cells and parenchyma of
the surrounding boundary layer and was low in the Rhizobium-infected
cells. This contrasts with the expression of both the P. andersonii
haemoglobin protein in P. andersonii nodules and the endogenous
Lotus leghaemoglobins that are expressed in the infected
cells at very high levels. The expression pattern of the P.
andersonii and T. tomentosa haemoglobin promoters in
L. corniculatus resembles that of a nonsymbiotic haemoglobin
gene from Casuarina glauca, which was introduced into this
legume, and suggests that only the nonsymbiotic functions of the
P. andersonii promoter are being recognized. Deletion of
the distal segments of both the P. andersonii and T.
tomentosa promoters identified regions important for the control
of their tissue-specific and temporal activity in Lotus.
Potential regulatory elements, which enhance nodule expression
and suppress nonnodule expression, were also identified and localized
to a distal promoter segment. A proximal AAGAG motif is present
in the P. andersonii, T. tomentosa, and nonsymbiotic Casuarina
haemoglobin genes. Mutation of this motif in the P. andersonii
promoter resulted in a significant reduction in both the nodule
and root expression levels in L. corniculatus. Some of
the regulatory motifs characterized are similar to, but different
from, the nodulin motifs of the leghaemoglobins.
Productivity and persistence of irrigated lotus (Lotus pedunculatus)
and white clover (Trifolium repens) in a kikuyu (Pennisetum
clandestinum) pasture. Fulkerson, W. J.; Slack, K. Tropical
Grasslands. 1996. V 30:353-362.
Lotus pedunculatus (L. uliginosus) cv. Sharnae and
Maku and Trifolium repens cv. Haifa were established in
a kikuyu (Pennisetum clandestinum) sward on the subtropical
north coast of New South Wales, Australia, in April 1992. Within
these pastures, all plots were defoliated by cutting at 5 or 12
cm stubble height with a 14 day or 'when ready' (lower leaves
commencing to senesce) interval in spring. In autumn-winter, lotus
plots were cut at 5 or 12 cm stubble height 'when ready', whereas
white clover plots were cut at 5 cm stubble height either every
14 days or 'when ready'. Irrigation replaced evapotranspiration
losses at 5-12-day intervals. Sharnae lotus showed substantially
earlier spring growth than Maku, but the annual yields of legume
and total herbage (legume plus kikuyu) were similar, with a mean
dry matter (DM) yield of pasture over the 2.5 years since sowing
of 34.08 t/ha, or 68% of the yield (49.88 t/ha) of white clover
pasture. The highest DM yields of legume (15.45 t/ha for lotus
and 24.10 t/ha for white clover) were obtained by defoliating
to 5 cm stubble height when the legume 'was ready' in spring for
white clover and also when lotus was again defoliated at 5 cm
height in autumn-winter. This treatment had no adverse effect
on growth of the kikuyu. Although there was a significant benefit
on total DM from delaying the commencement of severe defoliation
of lotus pasture (from 12 to 5 cm stubble height) in autumn (at
a time of expected rhizome growth) the effect was small at 4%
and was due to an 8% increase in kikuyu, rather than a change
in legume yield. In fact, growth of lotus rhizomes was confined
to winter-late spring, in contrast to summer-autumn in temperate
regions of Australia. The very low rate of seedling recruitment
from natural reseeding, or reseeding white clover in autumn, confirms
that attempts to increase its persistence in irrigated kikuyu
pastures must focus on strategies that will increase stolon survival,
particularly over summer. Management required to establish and
maintain a productive legume-kikuyu pasture for 2 years is relatively
clear but the cause of the decline in vigour of the legume component
after 2 years is less clear.
Inclusion of Dallis grass (Paspalum dilatatum Poir)
in swards: I. Effect on forage production. <Original>
Inclusion de pasto miel (Paspalum dilatatum Poir) en pasturas:
I. Efecto sobre la produccion forrajera. Acosta, G.; Deregibus,
A.; Zucchini, F. Revista Argentina de Produccion Animal. 1994.
V 14:175-185.
Pastures were established in Buenos Aires, Argentina, in September
1990 by transplanting individual plants of Lolium perenne +
Trifolium repens, Phalaris aquatica + T. pratense or Festuca arundinacea
+ Lotus corniculatus in mixture with 0, 25 or 50% Paspalum
dilatatum with grass species bearing 4-5 tillers and leguminous
species 4-5 buds to give a total density of 66 plants/m2. Swards
were cut to a height of 3 cm at <5% flowering of P. dilatatum
and subsequently at onset of senescence in basal leaves. Highest
annual forage DM yields were given by Phalaris aquatica + T.
pratense (6.70 t/ha) and inclusion of Paspalum dilatatum
increased average DM yields by about 30%, without reduction of
sward component yields. Since P. dilatatum reduced contribution
of spontaneous warm-season species, improved seasonal distribution
of available forage and total forage production, its inclusion
is recommended in pastures of the Argentinian Pampas region.
Nitrogen fixation in Trifolium repens, Lotus tenuis and
Festuca arundinacea pastures under two intensities of continuous
grazing. <Original> Fijacion de nitrogeno en pasturas
de Trifolium repens, Lotus tenuis y Festuca arundinacea
bajo dos intensidades de pastoreo continuo. Refi, R. O.; Navarro,
C. A.; Escuder, C. J. Revista Argentina de Produccion Animal.
1994. V 14:147-160.
In grazing trials in Balcarce, Argentina, in 1984-86, pastures
improved by over-sowing with mixtures of either inoculated seed
of Trifolium repens cv. El Lucero or Lotus tenuis ecotype
Monte with Festuca arundinacea cv. Palenque or Maris Kasba
in May were continuously grazed from autumn 1985 by bullocks at
stocking rates adjusted to maintain above-ground biomass at 800-1200
kg DM or 1800-2200 kg DM/ha. During 1986 measurement over 10 one-week
periods throughout the year showed that average annual N fixation
was <60 kg N/ha, reflecting the low sward legume content which
averaged 7-24% in paddocks. Maris Kasba was most compatible with
leguminous species, allowing better ground cover and N fixation.
El Lucero was more stable in cover and N fixation during the summer
but was inferior in spring and winter seasons.
The capacity for sulphur dioxide accumulation in herbage plants.
<Original> Capacitatea de acumulare a anhidridei sulfuroase
la plantele ierboase. Manole, A. Buletinul Academiei de Stiinte
a Republicii Moldova. Stiinte Biologice si Chimice. 1994. No.
6:10-13.
In 1991-93, S accumulation in grass and legume species grown in
(a) urban conditions or (b) the Moldavian Botanical Gardens was
determined. Grass and legume species with a fast or average speed
of development showed a higher accumulation of S and were most
affected at the end of the growing season (5.06 and 6.27 g/kg
dry weight in Lolium perenne, 6.12 and 6.53 g in Festuca
pratensis, and 3.6 and 4.47 g in Trifolium repens in
(a) and (b), respectively). Grass and legume species with a slower
speed of development (rhizomatous and bushy species) showed lower
S accumulation and were more resistant to damage during the whole
of the growing season (Festuca rubra, Poa pratensis, Trifolium
pratense, Lotus corniculatus).
Effect of mineral fertilizer application on the yield and botanical
composition of meadow grasses and grass mixtures in the Troyan
Region. Lingursky, V.; Totev, T.; Mihovsky, Ts.; Tankov, K.;
Churkova, V.; Georgieva, D.; Belperchinov, K. Rasteniev"dni
Nauki. 1995. V 32:190-193.
In field trials in 1989-92 on acid soils, grasses and grass/legumes
mixtures were given no fertilizers, or 80-240 kg N with or without
80 kg P and 80 kg K/ha. The response of legumes and grass/legume
mixtures to N with or without PK was limited, whereas pure swards
of Dactylis glomerata, Festuca rubra and Lolium perenne
showed yield increases of 209, 183 and 288%, respectively, at
the highest N rate. In mixed swards, N application favoured grasses
and weeds whereas PK application suppressed weeds and increased
legumes. 80 kg N/ha was the recommended rate for legumes (Lotus
sp., Trifolium repens and T. pratense), grass/legume
mixtures and L. perenne, and 160 kg N for D. glomerata
and F. rubra.
Investigation of sowing dates for perennial grass mixtures.
Stoeva, K. Rasteniev"dni Nauki. 1995. V 32:156-158.
In field trials in 1988-93 on leached cinnamon forest soil, pH
4.6, Lotus corniculatus, Dactylis glomerata, Festuca rubra
and Bromus inermis were grown alone or in 30%:70% grass-legume
mixtures. Sowing dates of 25-30 October, 25-30 November, 20-25
December and 20-25 March were compared. Spring sowing gave the
best results for L. corniculatus and for the establishment
of the mixtures. November and December sowing dates were preferable
for pure grass stands, with some seed not germinating until the
spring; these sowing dates were recommended for grass seed production.
Effect of cutting frequency on the productivity of permanent
grasslands. Chakarov, P.; Vasilev, E. Rasteniev"dni Nauki.
1995. V 32:149-151.
In field trials in 1989-92 on leached chernozem poor in N and
P but rich in K, the productivity of pure stands and mixtures
of Medicago sativa cv. Pleven 13 and Lotus corniculatus
cv. T''rgvishche 1 (Targovishte 1) with Dactylis glomerata
cv. D''brava (Dubrava) grown with or without irrigation and cut
at intervals of 30, 45 or 60 days was investigated. Pleven and
Dubrava were best cut at 45-day intervals, but L. corniculatus
and its mixture with Dubrava were best cut at 60-day intervals.
Increasing the cutting interval from 20 to 30 or even 40 days
increased the dry matter and crude protein yields of all swards.
Irrigation increased crude protein and dry matter yields. Crude
protein yields were highest in the Pleven + Dubrava mixture.
Comparison of conventional and alternative nursery field management
systems: tree growth and performance. Calkins, J. B.; Swanson,
B. T. Journal of Environmental Horticulture. 1996. V 14:142-149.
The effects of 5 nursery field maintenance systems (cultivation,
herbicide management using oxadiazon, a companion crop of Lotus
corniculatus, a rye cover crop/mulch, and mixed grass sward
of Lolium perenne cv. Eton and Festuca rubra cv.
Ruby) on the growth and performance of field-grown trees were
investigated in Minnesota. Six tree species were included in this
study: Fraxinus pennsylvanica cv. Marshall's Seedless,
Malus cv. Red Splendor, Gleditsia triacanthos var.
inermis cv. Skyline, Acer rubrum cv. Northwood,
Thuja occidentalis cv. Techny and Picea glauca var.
densata. Height, lateral branch extension, and caliper growth
(increase in trunk diameter 15 cm above soil level) were measured
each year for 7 years. Plant quality was assessed at the end of
the study. All growth parameters were affected by field management
treatment. Field management treatment effects on growth were influenced
by differences in climate between years and were species dependent.
Caliper growth was more sensitive to cover crop competition than
height growth. Height and caliper growth were initially reduced
for deciduous trees grown together with cover crops, but treatment
differences in height became less significant over time. Caliper
of evergreens was also reduced, but field management treatment
effects on height were variable. Trees grown under bare soil conditions
(cultivation or herbicide management) were more densely branched
than those grown with cover crops. Herbicide management and cultivation
generally supported the most vigorous growth and resulted in the
best quality plants. Of the cover/companion crops evaluated, the
rye cover crop/mulch treatment only slightly reduced plant performance
compared with cultivated and herbicide management treatments while
L. corniculatus and grass companion crops proved to be
too competitive. A winter rye cover crop/mulch field management
system appears to have potential as an alternative to conventional
field production systems. Using such a system, quality plants
can be produced with fewer inputs and fewer negative impacts on
the environment and long term productivity.
MsEnod12A expression is linked to meristematic activity during
development of indeterminate and determinate nodules and roots.
Bauer, P, Poirier, S.; Ratet, P.; Kondorosi, A. In: Molecular
plant-microbe interactions : MPMI. Jan 1997. v. 10:39-49.
During development of nodules and roots, the alfalfa early nodulin
gene MsEnod12A is expressed adjacent to the meristem. Using transgenic
alfalfa carrying a MsEnod12A promoter-gusA fusion, we investigated
the regulation of MsEnod12A expression in mature nodules and roots
by GUS assays and reverse transcription-PCR. We found that in
alfalfa indeterminate nodules induced by various Fix(-) Rhizobium
meliloti mutants and in spontaneous nodules devoid of rhizobia,
MsEnod12A was expressed at the distal end when a persistent meristem
was present. However, this gene was not expressed when the meristem
was lacking in nodules arrested in development. The MsEnod12A-gusA
fusion was introduced into Lotus corniculatus plants that
form determinate nodules devoid of a persistent meristem. Using
these plants we found MsEnod12A-gusA expression only in young
nodules and a disappearance in mature nodules. Moreover, when
alfalfa roots were treated with auxins a lateral band of MsEnod12A
expression was observed surrounding the club-shaped root apex
and coinciding with induced lateral meristematic activities. Thus,
in all cases MsEnod12A expression was associated with meristematic
activities, suggesting that MsEnod12A plays a role in the differentiation
processes of nodule and root cells and that it may serve as molecular
tool for analyzing meristem establishment during nodule development.
Legume lectins and nodulation by Rhizobium. Brewin,
N.J.; Kardailsky, I.V. In: Trends in plant science. Mar
1997. v. 2:92-98.
Oxygen-induced membrane depolarizations in legume root nodules.
Possible evidence for an osmoelectrical mechanism controlling
nodule gas permeability. Denison, R.F.; Kinraide, T.B. In:
Plant physiology. May 1995. v. 108:235-240.
Various stresses trigger rapid and reversible decreases in the
O2 permeability (P(O)) of legume root nodules. Several possible
mechanisms have been proposed, but no supporting data have previously
been presented that meet the requirements for both rapidity and
reversibility. Stomatal regulation of gas permeability in leaves
involves electrically driven fluxes of inorganic osmoticants,
so we investigated the possibility of a somewhat similar mechanism
in nodules. We used microelectrodes to monitor membrane potential
in intact, attached nodules of Glycine max, Medicago sativa,
Lotus corniculatus, and Trifolium repens while controlling
external O2 concentration and, in the case of G. max,
measuring P(O) with a nodule oximeter. A 1- to 2-min exposure
to 100 kPa O2 was found to induce rapid and reversible
membrane depolarizations in nodules of each species. This depolarization
(which, to our knowledge, is unique to nodules) is accompanied
by reversible decreases in P(O) in G. max nodules. An osmoelectrical
mechanism for control of nodule gas permeability, consistent with
these data, is presented.
Classical and molecular genetics of the model legume Lotus
japonicus. Jiang, Q.; Gresshoff, P.M. In: Molecular
plant-microbe interactions : MPMI. Jan 1997. v. 10:59-68.
The model legume Lotus japonicus was demonstrated to be
amenable to classical and molecular genetic analysis, providing
the basis for the genetic dissection of the plant processes underlying
nodulation and nitrogen fixation. We have developed an efficient
method for the sexual hybridization of L. japonicus and
obtained F1 progeny derived from a cross of L. japonicus
B-129-S9 Gifu X B-581 Funakura. Over half of the cross-pollinations
resulted in fertile hybrid seed, which were confirmed morphologically
and by single arbitrary primer DNA amplification polymorphisms
using the DAF technique. Molecular and morphological markers segregated
in true Mendelian fashion in a F2 population of 100 plants. Several
DAF loci were linked using the MAPMAKER software to create the
first molecular linkage groups of this model legume. The mapping
population was advanced to generate a set of immortal recombinant
inbred lines (F6; RILs), useful for sharing plant material fixed
genetically at most genomic regions. Morphological loci for waved
stem shape (Ssh), dark leaf color (Lco), and short flowering period
(Fpe) were inherited as single dominant Mendelian loci. DAF markers
were dominant and were detected between Gifu and Funakura at about
one per primer, suggesting that the parents are closely related.
One polymorphism (270G generated by single octomer primer 8.6m)
was linked to a morphological locus controlling leaf coloration.
The results demonstrate that (i) Lotus japonicus is amenable
to diploid genetic analysis, (ii) morphological and molecular
markers segregate in true diploid fashion, (iii) molecular polymorphisms
can be obtained at a reasonable frequency between the related
Gifu and Funakura lines, and (iv) the possibility exists for map-based
cloning, marker assisted selection and mapping of symbiotic mutations
through a genetic and molecular map.
Genetically engineered plants producing opines alter their
biological environment. Oger, P.; Petit, A.; Dessaux, Y. In:
Nature biotechnology. Apr 1997. v. 15:369-372.
Differential expression of the Sesbania rostrata leghemoglobin
glb3 gene promoter in transgenic legume and non-legume plants.
Szczyglowski, K., Potter, T.; Stoltzfus, J.; Fujimoto, S.Y.;
Bruijn, F.J. de. In: Plant molecular biology. July 1996.
v. 31:931-935.
The involvement of the Sesbania rostrata glb3 gene promoter
NICE (nodule-infected cell expression) element in root-enhanced
expression of 5'-Srglb3-uidA-3'nos chimeric gene was investigated
in transgenic Nicotiana tabacum plants. The full-length
wild-type Srglb3 promoter directed root meristem-enhanced expression
in transgenic tobacco plants. The expression pattern of nine selected
Srglb3 promoter mutations in the NICE element was examined in
transgenic tobacco plants and compared with the pattern observed
in nodules of transgenic Lotus corniculatus plants. The
results suggest that the highly conserved motifs in the NICE element
play an important role in expression in roots of non-legume plants.
Molecular cloning and characterisation of asparagine synthetase
from Lotus japonicus: Dynamics of asparagine synthesis
in N-sufficient conditions. Waterhouse, R.N.; Smyth, A.J.;
Massonneau, A.; Prosser, I.M.; Clarkson, D.T. In: Plant
molecular biology. Mar 1996. v. 30:883-897.
Two cDNA clones, LJAS1 and LJAS2, encoding different asparagine
synthetases (AS) have been identified and sequenced and their
expression in Lotus japonicus characterised. Analysis of
predicted amino acid sequences indicated a high level of identity
with other plant AS sequences. No other AS genes were detected
in the L. japonicus genome. LJAS1 gene expression was found
to be root-enhanced and lower levels of transcript were also identified
in photosynthetic tissues. In contrast, LJAS2 gene expression
was root-specific. These patterns of AS gene expression are different
from those seen in pea. AS gene expression was monitored throughout
a 16 h light/8 h dark day, under nitrate-sufficient conditions.
Neither transcript showed the dark-enhanced accumulation patterns
previously reported for other plant AS genes. To evaluate AS activity,
the molecular dynamics of asparagine synthesis were examined in
vivo using 15N-ammonium labelling. A constant rate of asparagine
synthesis in the roots was observed. Asparagine was the most predominant
amino-component of the xylem sap and became labelled at slightly
slower rate than the asparagine in the roots, indicating that
most root asparagine was located in a cytoplasmic 'transport'
pool rather than in a vacuolar 'storage' pool. The steady-state
mRNA levels and the 15N-labelling data suggest that light regulation
of AS gene expression is not a factor controlling N-assimilation
in L. japonicus roots during stable growth in N-sufficient
conditions.
Seed dispersal capacity of six perennial grassland species
measured in a wind tunnel at varying wind speed and height. Dorp,
D. van; Hoek, W. P. M. van den; Daleboudt, C. Canadian Journal
of Botany. 1996. V 74:1956-1963.
The dispersal capacity of six perennial grassland species with
different seed aerodynamic attributes (Centaurea jacea, Hypericum
quadrangulum, Lotus uliginosus, Lychnis flos-cuculi, Peucedanum
palustre and Thalictrum flavum) was assessed in a wind
tunnel. The selected species have difficulty in recolonizing restored
ecosystems because of poor seed dispersal. The variation in dispersal
distances of seeds within and between species was assessed by
releasing seeds at varying wind speeds and release heights, expressed
as 1st percentile, mode and 99th percentile values. Dispersal
distances of long-range dispersed seeds (99th percentile values)
increased exponentially with wind speed. At wind speeds of 14
m/s, predicted maximum distances were found to be 10-15 m for
small and relatively heavy spherical seeds and 20-30 m for large
and relatively light cylindrical or disc-like seeds. In the study
area (near Wageningen), wind gusts of >10 m/s at plant height
occur at least annually, and plants of the selected species live
up to several decades. This suggests a great potential for long-range
dispersal during the lifetime of a plant. Plants may effect wider
dispersal of seeds by increasing the release height (e.g. by taller
infructescences) and by requiring stronger winds to release seeds
(e.g. by dispersal in autumn and winter).
Soil rehabilitation and erosion control through agro-ecological
practices on Reunion Island (French Overseas Territory, Indian
Ocean). Perret, S.; Michellon, R.; Boyer, J.; Tassin. J. Agriculture,
Ecosystems & Environment. 1996. V 59:149-157.
The erosion problems caused by cropping of perfume Pelargonium
species in the title region and the consequences of this deterioration
are reviewed, and the agro-ecological solutions using cover plants
and hedging with agroforestry species is assessed. The short term
effects of cover plants (Lotus uliginosus, Pennisetum clandestinum)
associated with the Pelargonium crop had immediate effects
in controlling erosion, although runoff was not significantly
reduced. The more long-term effects of this type of cover were
compared with Pelargonium monoculture on bare soils, and
with Pelargonium in rotation with stable crops. The effect
of hedging (Calliandra spp.) along plot boundaries was
also observed. Descriptions of soil profiles highlighted the advantages
of plant cover in improving soil structure and biological activity.
Near hedges, the same tendencies were even more marked. Soil hydraulic
conductivity measurements confirmed the complementarity of cover
plants and hedges in association. Plant cover reduced erosion,
with only a slight increase in water infiltration. At the same
time, soil under hedges had very high water conductivity which
should enable a large proportion of runoff water infiltrate.
A taxonomic evaluation of Lotus corniculatus Linn. (Leguminosae-Papilionoideae)
in India. Chaudhary, L. B. Taiwania. 1996. V 41:168-173.
Although Lotus corniculatus in India is highly variable,
no infraspecific taxa have been recognised because of the overlapping
variation shown by different populations. A critical study of
the collections in 5 Indian herbaria reveals that the species
varies mainly in pubescence character, shape and size of leaflets
and number of flowers, often within the same population. The varieties
L. corniculatus var. japonicus and L. corniculatus
var. minor have been reduced here as synonyms under L.
corniculatus.
Investigation on the productivity and intolerance of desert
wheatgrass (Agropyron desertorum Roem et Schult.) in mixture
with lucerne, trefoil and sainfoin. Shamov, D. Rasteniev"dni
Nauki. 1995. V 32:55-57.
In field trials in 1988-90 on cinnamon forest soils, A. desertorum
was grown in mixtures of different proportions (25, 50 and 75%)
with Medicago sativa, Lotus corniculatus and Onobrychis viciifolia.
Mixtures with L. corniculatus were not successful as A. desertorum
proved too competitive. The three most productive swards were
50% grass + 50% O. viciifolia, 25% grass + 75% O. viciifolia
and pure O. viciifolia at 10.54, 11.09 and 10.51 t dry
matter/ha, respectively.
The phasing of temporary pasture production using mixtures
formed of cultivars with different vegetative periods. <Original
title> Esalonarea productiei pajistilor temporare prin utilizarea
amestecurilor formate din soiuri cu perioda diferata de vegetatie
(1). Popovici, D.; Ciubotariu, C.; Tonigar, D. Statiunea de Cercetari
Agricole, Suceava, Romania. Cercetari Agronomice in Moldova. 1996.
V 29:191-197.
In 1991-95 at Suceava, the yield response of 15 mixtures of Dactylis
glomerata, Lolium perenne, Phleum pratense, Festuca pratensis,
Festuca arundinacea, Poa pratensis, Bromus inermis, Trifolium
repens and Lotus corniculatus cultivars with different
growing seasons were grown for hay and for grazing. Dry matter
yields ranged from 7.72 to 8.86 t/ha, 8.83 to 9.42 t and 9.63
to 9.90 t for hay and from 7.67 to 8.59 t, 7.17 to 7.91 t and
7.36 to 7.48 t for grazing with early, mid-season and late cultivars,
respectively. P. pratensis was useful in swards for grazing and
in dry areas it was considered worthwhile to replace F. pratense
with B. inermis cv. Orfeu.
Contributions on the establishment of mixtures of perennial
plants for temporary hay mixtures, used for grazing, in the lower
Jijia Valley and Bahlui. <Original title> Contributii
la stabilirea amestecului de ierburi perene pentru infiintarea
pajistilor temporare, folosite prin pasunat, in Depresiunea Jijei
inferioare si a Bahluiuilui. Vintu, V.; Iacob, T.; Dumitrescu,
N.; Samuil, C. Universitatea Agronomica, Iasi, Romania. Cercetari
Agronomice in Moldova. 1996. V 29:185-189.
In 1993-95 at Iasi on a slightly leached cambic chernozem on temporary
pastures, dry matter yields were 5.09 t/ha with 50% Bromus
inermis + 50% Onobrychis viciifolia, 6.23
t with 20% Dactylis glomerata + 30% Lolium
perenne + 50% Medicago sativa and 6.75 t with 25%
Festuca pratensis + 25% L. perenne + 10%
Agropyron pectiniforme (A. cristatum subsp. pectinatum)
+ 10% Lotus corniculatus + 30% M. sativa and ranged
from 4.92 t with no fertilizers to 7.12 t with 200 kg N/ha.
Chemical analysis of flavonoids in uninoculated and Rhizobium-challenged
or infected roots of Lotus pedunculatus. Smartt,
S. A.; Rao, J. R.; Bjourson, A. J.; Cooper, J. E. <Eds>
Geibel, M.; Treutter, D.; Feucht, W. Acta Horticulturae. 1994.
No. 381:158-161. International symposium on natural phenols in
plant resistance, Volume I, Weihenstephan, Germany, 13-17 September
1993.
The effect of closing date on seed production from a birdsfoot
trefoil (Lotus corniculatus L.) pasture. Bologna, J.
J.; Rowarth, J. S.; Fraser, T. J. Journal of Applied Seed Production.
1996. V 14:47-52.
The effect of closing date on seed production and quality from
a Lotus corniculatus pasture at Lincoln, New Zealand, was
examined by removing sheep (closing) on 18 November or 20 December
1994 or 10 January 1995. Seed yield did not differ for the November
and December closing dates, but was significantly reduced (from
65.1 g m-2 to 45.8 g m-2) by the January
closing. Seed quality parameters, especially seed viability, germination
and 1000-seed weight were superior from the November and December
closing dates. Closing date did not affect the number of mature
pods or mean pod length at seed harvest. Seed weight and shoot
density were the most important factors affecting final seed yield.
It is concluded that defoliation of L. corniculatus pasture
during November or December is unlikely to decrease seed production,
provided that environmental conditions are suitable for rapid
plant recovery.
Phenological and physiological characterization of autochthonous
legumes of the steppe in Syria. <Original title> Phanologische
und physiologische Charakterisierung autochthoner Steppenleguminosen
in Syrien. Kattach, G. Fachbereich Agrarwissenschaften und Umweltsicherung,
Justus Liebig Universitat Giessen, Germany. 1995.
Sixty sites on the Syrian steppe were studied in 1991 and 235
leguminous ecotypes belonging to 42 species and 13 genera were
identified. Species in the genera Astragalus and Trigonella
had the highest abundance, especially in the driest areas. Trifolium
occurred in humid areas and Medicago in areas with rainfall
exceeding 100 mm. Positive relationships were found between species
diversity and rainfall, soil nitrogen content, organic matter
content and available phosphorus. There were marked differences
in seed production among the species. Astragalus and Trigonella
produced the most seeds. In one third of the sites studied there
were no seeds in the soil, suggesting that there was a risk of
genetic erosion. Under standardized conditions in the greenhouse
the genotypes showed marked differences in their phenological
(vegetative and generative), morphological and reproductive characteristics.
Ecotypes found in drier areas had a short phenological phase,
thicker leaves, smaller leaf area, lower 100 pod mass, pod length,
number of seeds per pod and 100 seed mass, and higher root mass
and seed and pod yield than those found in humid areas. The species
of the genus Astragalus showed higher germination rates
than that of Trigonella. Under field conditions the genotypes
showed wide variability in establishment, flowering time, fruiting,
morphology, plant density, feed value (dry matter and crude protein
content) and leaf area index. Lotus peregrinus, T. stellata
and T. schlumbergeri were very sensitive to low temperatures,
whereas all the other species investigated were frost tolerant.
Influence of phosphorus nutrition on mycorrhizal growth response
and morphology of mycorrhizae in Lotus tenuis. Mendoza,
R. E.; Pagani, E. A. Centro de Ecofisiologia Vegetal (CONICET),
Serrano 669, 1414 Buenos Aires, Argentina. Journal of Plant Nutrition.
20:625 639. 1997.
In a greenhouse experiment, Lotus tenuis was grown on a
P deficient soil, sterilized or not sterilized, in pots and given
0 160 micro g P/g soil. Glomus fasciculatum was indigenous
to the soil. Non mycorrhizal plants required 1.5 times more added
P to obtain the same yield as mycorrhizal plants. Nevertheless,
the relationship between the P concentration in shoots and the
dry weight of shoots was the same for both mycorrhizal and non
mycorrhizal plants suggesting that differences in growth reflect
differences in the uptake of P rather than its utilization within
the plant. The length of root infected (HC) and the fraction of
infected roots containing arbuscules (AC) initially increased
at low levels of added P, and then with further additions, they
decreased. The number of entry points per unit of root length
infected decreased with increasing P concentration in the shoots.
The ratio between the number of entry points and hyphal and arbuscule
density decreased at low P and then increased with increasing
added P. Thus, the morphology of the mycorrhiza was altered by
P nutrition. It was concluded that at the lower levels of added
P, the low P soil status inhibited both the spread of the fungus
within the root and the growth of the roots.
Sodseeding on a subtropical rangeland in Mexico. Ricardo,
A.; Medina, S.; Cano, E.; Ramirez, N.; Chavez, J. O. In
West, N. E. (Ed) Rangelands in a sustainable biosphere. Proceedings
of the Fifth International Rangeland Congress, Salt Lake City,
Utah, USA, 23 28 July, 1995. Volume 1. Society for Range Management,
Denver
Effects of oversowing 7 species (Lotus corniculatus, Trifolium
repens, Neonotonia wightii, Teramnus labialis, Dactylis glomerata,
Lolium multiflorum and Panicum maximum) on the net
herbage production and nutritive value of a humid subtropical
rangeland (with Axonopus compressus and Paspalum notatum)
in Mexico were evaluated. Tropical species failed to establish.
Direct sowing of rangeland with Lotus corniculatus improved
the nutritive value of herbage and may be used increase animal
production at low cost without the risk of erosion.
Dactylis polygama Horvat. in clover grass mixtures.
<Original title> Srha hajni (Dactylis polygama Horvat.)
v jetelovinotravnich smesich. Mika, V.; Smrz, J.; Pelikan, J.
Institute of Agricultural and Food Information, Research Station
of Grassland Ecosystems, Jevicko, Czech Republic. Rostlinna Vyroba
43:137 142. 1997.
Dactylis polygama (Dactylis glomerata subsp.
polygama, DP) new selection CD was compared in trials with
Dactylis glomerata (D. glomerata subsp. glomerata,
DG) cv. Niva in a number of grass/legume mixtures formulated for
short, medium and long term use. DP mixtures with other grasses
and legumes provided a dense and even stand without suppressing
Trifolium spp. and resisting penetration from invasive
weeds such as Taraxacum officinale in the first 2 years.
DP grown with Lotus corniculatus was particularly promising
with good persistence of the legume and low occurrence of weeds
for 4 years. The growth rhythm of DP was better harmonized with
Medicago sativa and Trifolium pratense (particularly
tetraploid cv. Tempus) than that of DG. The competitive ability
of DP is weak and similar to that of Festuca pratensis.
Fresh weight yields of mixtures with DP were 1.7 6.2% lower than
in mixtures with DG. The mixture of DP with Festuca rubra,
Lolium perenne, Festuca pratensis and Poa pratensis
was considered suitable for temporary and extensively used grasslands,
orchards, vineyards and land diversion (setaside). DP was more
tolerant of shading but less tolerant of drought than DG.
The copper, manganese, zinc and iron contents in legume leaves
sampled in natural meadow habitats. <Original title>
Zawartosc miedzi, manganu, cynku i zelaza w lisciach roslin motylkowatych
z naturalnych siedlisk lakowych. Grzegorczyk, S. Zaklad Lakarstwa,
ART, Plac Lodzki 1, 10 957 Olsztyn, Poland. Zeszyty Problemowe
Postepow Nauk Rolniczych 434:569 573. 1996.
In studies of 81 natural meadow communities with high proportions
of legumes (Lotus corniculatus, L. uliginosus, Trifolium repens
and T. hybridum) in the Olsztyn lakeland area in 1993
95, Mn, Fe, Cu and Zn contents of soils and legume leaves were
determined. Leaf Mn content ranged from 51.3 mg/kg dry matter
in L. corniculatus to 98.5 mg/kg in L. uliginosus,
Fe content from 198.1 mg/kg in L. uliginosus to 406.9 mg/kg
in T. repens, Cu content from 5.4 mg/kg in L. uliginosus
to 9.6 mg/kg in T. hybridum and Zn content from 27.0 mg/kg
in T. repens to 46.0 mg/kg in L. uliginosus. Leaf
Mn and Zn contents were positively correlated with soil pH and
leaf Zn content with soil Zn content.
The effect of soil conditions on the content of trace elements
in pasture herbage. <Original title> Wplyw warunkow
glebowych na zawartosc mikroelementow w roslinnosci pastwiskowej.
Warda, M.; Krzywiec, D.; Cwintal, H. Katedra Lakarstwa, AR, ul.
Akademicka 15, 20 950 Lublin, Poland. Zeszyty Problemowe Postepow
Nauk Rolniczych 434:.537 542. 1996.
In newly established trials on chernozem (pH 4.0) and peat muck
(pH 5.1) soils, contents of B, Cu, Zn, F and Mn were determined
in the surface soil layer and in Lolium perenne, Dactylis glomerata,
Phleum pratense, Trifolium repens, Lotus corniculatus, Medicago
lupulina, M. sativa and weeds (predominantly Taraxacum
officinale). Contents of all the trace elements were considerably
higher in the peat muck soil than in the chernozem. On the chernozem,
B content was <5 p.p.m. in the grasses, 16 30 p.p.m. in the
legumes and 23 p.p.m. in the weeds. Cu content was higher on the
peat muck soil, especially in L. perenne and M. sativa
and was lowest (2.6 p.p.m.) in P. pratense and highest
(7 8 p.p.m.) in weeds on both soils. Zn content was higher on
chernozem, except in weeds, and was lowest (28 30 p.p.m.) in T.
repens. There were significant differences in Fe and Mn contents
between soil types and species. The Fe:Mn ratio was below the
optimum range of 1.5 2.5 except in T. repens on both soils
and in the other legumes on chernozem soil, and was very low in
D. glomerata on peat muck soil. The value of legumes in
compensating for B and Cu deficiency in pasture is noted.
Establishment and persistence of legumes interseeded into switchgrass.
Blanchet, K.M.;George, J.R.; Gettle, R.M.; Buxton, D.R.; Moore,
K.J. 1995. Agronomy Journal. 87:935-941.
Little information is available for renovation of established
switchgrass (Panicum virgatum L.) with cool-season forage
legumes. Field experiments were conducted to determine seeding
success, persistence, and impact on grass when 10 forage legumes
and a legume mixture were no-till interseeded into established
'Cave-in-Rock' switchgrass near Ames, IA. Legumes interseeded
in early April 1991 and 1992 were biennial 'Polara' white-flowered
sweetclover (Melilotus alba Medik.) and 'Madrid' yellow-flowered
sweetclover (Melilotus officinalis Lam.), 'Norcen' and
'Fergus' birdsfoot trefoil (Lotus corniculatus L.), 'Apollo
Supreme' and 'Alfagraze' alfalfa (Medicago sativa L.),
Mammoth end 'Redland II' red clover (Trifolium pratense
L.), 'Emerald' crownvetch (Coronilla varia L.), common
hairy vetch (Vicia villosa Roth.), and a 50:50 mixture
of Norcen trefoil and medium red clover. Legume innovation was
compared with grass fertilized with N at 0, 60, 120, and 240 kg
ha-1. Excellent legume establishment was observed in
June, about 2.5 mo after interseedings, with mean legume plant
density of 195 and 163 plants m-2 for 1991 and 1992
seedings, respectively. Both alfalfa cultivars and hairy vetch
had highest percentage establishment. Average legume persistence
to June of the second year was nearly 50% for 1991 and 30% for
1992 seedings (less in 1992 because of greater winter losses).
Grass stem density during the establishment year was not affected
by legume renovation. Decline in grass stems during the second
year was greatest for trefoil and the trefoil-red clover mixture,
and intermediate for alfalfa and red clover, with minimal to no
effect for the sweetclovers, crownvetch, and hairy vetch. Hence,
legumes can be successfully established into switchgrass and can
be maintained into the second year.
The origin of the Lotus corniculatus (Fabaceae) complex:
a synthesis of diverse evidence. Grant, W.F.; Small, E. 1996.
Canadian Journal of Botany. 74:975-989.
The dynamics of experimental arable weed communities under
different management practices. McCloskey, M.; Firbank, L.G.;
Watkinson, A.R.; Webb, D.J.. 1996. Journal of Vegetation Science7:799-808.
Forage legumes : clovers, birdsfoot trefoil, cicer milkvetch,
crownvetch, sainfoin and alfalfa. St. Paul, Minn.: Minnesota
Agricultural Experiment Station, University of Minnesota, 1993.
40 p.
Stability of CaMV 35S-gus gene expression in (Bird's foot trefoil)
hairy root cultures under different growth conditions. Cooke,
D.E.; Webb, K.J. Plant Cell, Tissue and Organ Culture. 1996/1997.
v. 47 (2), p. 163-168.
Lotus corniculatus is an agronomically important forage
legume. Genetic engineering offers opportunities both to improve
L. corniculatus as a crop and to increase basic understanding
of plant biochemistry and metabolism. Biosynthesis of secondary
products and nitrogen fixation are two areas in which gene expression
has been studied using hairy root cultures of L. corniculatus.
The stability of foreign gene expression in these cultures is
critically important. Two L. corniculatus root culture
lines containing a reporter gene (CaMV 35S-gus) were used to investigate
the stability of expression of a foreign gene under a range of
conditions likely to be encountered in experiments. The hairy
root culture lines were grown under varying conditions of light,
temperature, nutrient supply, and in the presence of the auxin
2,4-D, or the elicitor glutathione. Expression of the gus gene,
detected by measuring GUS activity, was found to be relatively
stable under all of the conditions investigated.
Steadfast trefoil's a survivor. Cooke, L. Agricultural
Research / Sept 1997. v. 45 (9), p. 22.
Nitrate effects on nodule oxygen permeability and leghemoglobin.
Nodule oximetry and computer modeling. Denison, R.F.; Harter,
B.L. Plant Physiology. Apr 1995. v. 107 (4), p. 1355-1364.
Two current hypotheses to explain nitrate inhibition of nodule
function both involve decreased O2 supply for respiration
in support of N2 fixation. This decrease could result
from either (a) decreased O2 permeability (P(O)) of
the nodule cortex, or (b) conversion of leghemoglobin (Lb) to
an inactive, nitrosyl form. These hypotheses were tested using
alfalfa (Medicago sativa L. cv Weevlchek) and birdsfoot
trefoil (Lotus corniculatus L. cv Fergus) plants grown
in growth pouches under controlled conditions. Nodulated roots
were exposed to 10 mM KNO3 or KCl. Fractional oxygenation of Lb
under air (FOL(air)), relative concentration of functional Lb,
apparent P(O), and O2-saturated central zone respiration rate
were all monitored by nodule oximetry. Apparent P(O) and FOL(air)
in nitrate-treated nodules decreased to <50% of values for
KCl controls within 24 h, but there was no decrease in functional
Lb concentration during the first 72 h. In nitrate-treated alfalfa,
but not in birdsfoot trefoil, FOL(air), apparent P(O), and O2-saturated
central zone respiration rate decreased during each light period
and recovered somewhat during the subsequent dark period. This
species difference could be explained by greater reliance on photoreduction
of nitrate in alfalfa than in birdsfoot trefoil. Computer simulations
extended the experimental results, showing that previously reported
decreases in apparent P(O) of Glycine max nodules with
nitrate exposure cannot be explained by hypothetical decreases
in the concentration or O2 affinity of Lb.
Frost-seeding legumes into established switchgrass: forage
yield and botanical composition of the stratified canopy. Gettle,
R.M.; George, J.R.; Blanchet, K.M.; Buxton, D.R.; Moore, K.J.
Agronomy Journal. July/Aug 1996. v. 88 (4), p. 555-560.
Grasses need adequate N for optimum herbage yield. Legumes could
be grown in mixed swards with switchgrass (Panicum virgatum
L.) to provide symbiotic N and replace the need for N fertilization,
extend the growing season because C3 species begin growth earlier
and continue growth later into the growing season, and increase
dry matter (DM) yield. The objective of this field study on a
Webster-Nicollet soil (fine-loamy, mixed, mesic, Typic Haplaquoll-Aquic
Hapludoll) at Ames, IA, was to compare herbage DM yield and botanical
composition for legume-renovated switchgrass with that of N-fertilized
switchgrass. Five inoculated forage legumes and a legume mixture
were frost-seeded into an excellent stand of established 'Cavein-Rock'
switchgrass in mid-March of 1991 and 1992. Grass-legume DM yield
was compared with N fertilization (0, 60, 120, and 240 kg ha-1)
in the seeding year (YR 1) and the second year (YR 2). Harvested
samples were separated into grass and legume components, and further
divided into upper and basal canopy. Nitrogen fertilization provided
greatest upper and basal canopy yields in both June and July of
YR 1. By June YR 2, legume renovation increased upper-canopy yields
more than for 240 N. Upper-canopy YR 2 yields of grass-legume
mixtures seeded in 1991 remained greater than for 240 N in July,
and were similar to 120 N in August. During a wetter and cooler
than normal summer, YR 2 yields of upper-canopy grass-legume mixtures
seeded in 1992 were similar to 60 and 120 N by July, and similar
to both unfertilized and N-fertilized switchgrass by August. We
concluded that yields of legume-renovated switchgrass were generally
greater than for mid to high levels of N fertilization during
YR 2. Because of relatively low herbage production during YR 1,
producers should consider frost-seeding legumes into only pan
of existing switchgrass pastures, while fertilizing the remaining
nonrenovated pasture with N to maintain high forage supply and
pasture productivity.
Specificity in the symbiotic association of Lotus corniculatus
and Rhizobium loti from natural populations. Lieven-Antoniou,
C.A.; Whittam, T.S. Molecular Ecology. July 1997. v. 6 (7), p.
629-639.
In vitro selection for improved seedling vigour in birdsfoot
trefoil (Lotus corniculatus L.). McLean, N.L.; Nowak,
J. Canadian Journal of Plant Science. July 1997. v. 77 (3), p.
385-390.
PZF, a cDNA isolated from Lotus japonicus and soybean
root nodule libraries, encodes a new plant member of the RING-finger
family of zinc-binding proteins. Schauser, L.; Christensen,
L.; Borg, S.; Poulsen, C. Plant Physiology. Apr 1995. v. 107 (4),
p. 1457-1458.
Mutations conferring azide resistance enhance symbiotic nitrogen
fixation in Rhizobium loti. Sharma, S. B.; Sakadevan,
K.; Sunila Sharma. Plant and Soil. 1997. 189:221-229.
Azide-resistant (AzR) mutants of Rhizobium loti strain
NZP2037 were isolated. Mutations conferring azide resistance (azi)
appeared at a frequency of 0.5 x 10-7. Nine AzR mutants of R.
loti were characterized for their symbiotic behaviour with
Lotus pedunculatus plants. In comparison with the wild
type parent strain, AzR mutants exhibited either similar or higher
symbiotic effectiveness. The azi mutations which enhanced nitrogen
fixation as well as improving shoot dry weight of the inoculated
plants also increased nodulation. Unlike several azi mutations
in Escherichia coli, these azi mutations did not alter
sensitivity of R. loti to phenethyl alcohol. One of the
AzR mutants exhibited higher micro-aerobic N',N',N',N'-tetramethyl-p-phenylenediamine
(TMPD) oxidase activity.
Evaluation of agronomic traits in tissue culture-derived progeny
of bird's-foot trefoil. Nikolic, R.; Mitic N.; Neskovic, M.
Plant Cell, Tissue and Organ Culture. 1997. 48:67-69.
Two newly selected Lotus corniculatus cultivars (Bokor
and Zora), introduced recently as pasture legumes, were studied
with respect to their in vitro regeneration capacity and field
performance of R1 regenerants. Callus tissue was formed on a medium
containing 2.7 micro M NAA, 18 micro M 2,4-D and 18 micro M kinetin
in 72-90% of explants in both cultivars. Organogenic capacity
was dependent on the explant type, and was highest in petiole-derived
calluses. Multiple buds were induced in callus tissues derived
from apical buds, petioles, leaf and cotyledon explants. The rooted
regenerants, acclimated in a greenhouse, were fertile. Seeds from
the R1 generation were sown in the field and the plants found
to be superior to controls in stem height and green mass production.
Effect of application of 'adhesive agents' on pod dehiscence
and seed yield in birdsfoot trefoil (Lotus corniculatus
L.) (A short communication). Hruskova, H.; Hofbauer, J. Scientific
Studies - Research Institute for Fodder Plants (Troubsko). 1996.
14:51-53.
In 1992-94 in the greenhouse and in 1993 and 1994 in the field
in the Czech Republic, pods of Lotus corniculatus cv. Lotar
or Vigl'assky grown for seed were sprayed with adhesive agents
to prevent seed shattering. The green pod stage was the most successful
period for application. The lowest pod dehiscence occurred in
pot-grown plants sprayed with 2 parts Sloviol R-16 (polyvinyl
alcohol) + 3 parts water and a wetting agent. Field treatment
with this substance increased seed yields by 20% in 1993 and 28%
in 1994. Sloviol R-16 was considered too expensive for normal
field use but use of Supergel or Spodnam DC (di-1-p-methane +
metabolic adjuvant) also reduced dehiscence and the cost was considered
reasonable in relation to expected seed yield increases.
Selection of embryogenic genotypes of the genus Lotus
and possibilities of their utilization. Repkova, J. Scientific
Studies - Research Institute for Fodder Plants (Troubsko). 1996.
14:33-37.
Lotus corniculatus, L. uliginosus and L. ornithopodioides
were investigated for their regeneration potential from callus
of vegetative explants. A liquid Murashige and Skoog medium with
10% of the concentration of plant nutrients, 25% of the concentration
of vitamins, 25% of the concentration of inositol, the full Fe
concentration and 10% sucrose solution was used. Seedlings of
L. conimbricensis were also cultured in R3 medium. Various
concentrations of BAP (benzyladenine), NAA and IAA were added
to the media. Differences in the regeneration potential of different
cultivars of L. corniculatus were observed with cv. Vigl'assky
the most successful. All explants of L. uliginosus died.
In L. ornithopodioides hypocotyls and apical meristems
formed callus but cotyledons did not. In L. conimbricensis
the regeneration of 3-day-old seedlings was 100%.
Post-burn recovery in the flooding Pampa: impact of an invasive
legume. . Laterra, P. Journal of Range Management. 1997. 50:274-277.
Winter burning of Paspalum quadrifarium stands ("pajonales")
promotes colonization of denuded spaces by several alien species.
Lotus tenuis ("lotus"), a recent invader of the
region, is able to reach very high densities between the resprouting
bunches of the dominant species. Results of a removal experiment
performed to evaluate the impact of natural establishment of lotus
on post-burn colonization of pajonal stands are reported. Seedlings
of lotus were removed shortly after their emergence between burned
bunches of P. quadrifarium. Eighty days after burning,
approximately 30% of the soil surface remained uncovered within
removal plots, whereas canopy cover was complete within controls.
Furthermore, final (137 days post-burn) total aboveground biomass
was 2.7 times higher in control than in removal plots. Removal
of lotus significantly (P<0.05) increased the cover of an annual
native grass (Phalaris angusta) and the final biomass of
an alien thistle (Carduus acanthoides). A spatial association
analysis provided additional evidence about the negative impact
of lotus on colonization success of C. acanthoides. It
is suggested that weed colonization may be reduced, if not prevented,
by managing the colonization processes of other new and useful
invaders.
The response of some perennial legume species and cocksfoot
cultivars in mixtures. <Original> Comportarea in amestec
a unor specii de leguminoase perene cu diferite soiuri de golomat.
Burcea, M.; Stefan, D. Lucrari Stiintifice - Universitatea de
Stiinte Agronomice Bucuresti. Seria A, Agronomie. 1995. 38:99-106.
In 1988-93 at Moara Domneasca on a reddish-brown soil, 4 Dactylis
glomerata cultivars were grown in mixtures with Trifolium
repens, Medicago sativa, Lotus corniculatus or Trifolium
pratense. Mean DM yields were 8.95, 8.70, 8.46 and 8.51 t/ha
in D. glomerata cv. Olimp, Poiana, Goliat and Intensiv,
respectively, plus legume species and ranged from 7.32 t with
D. glomerata + M. sativa to 10.48 t with D. glomerata
+ T. pratense + T. repens. Between the 1st and
4th cuts, T. repens competed well with D. glomerata
in year 1 but disappeared from the mixture by year 3. M. sativa
developed more slowly and was 5% of the mixture in year 1
but became dominant in year 3. D. glomerata and L. corniculatus
maintained a similar mixture over the 3-year period.
Responses of Lotus corniculatus to environmental change.
I. Effects of elevated CO2, temperature and drought
on growth and plant development. Carter, E. B.; Theodorou,
M. K.; Morris, P. New Phytologist. 1997. 136:245-253.
Five clonal plants of three genotypes of Lotus corniculatus
were grown in each of eight controlled environments under combinations
of two temperature regimes (18/10 C and 25/15 C), two CO2
concentrations (ambient and twice ambient) and two water applications
(ad libitum or 60% droughted). Plants were harvested at full flower
and measurements made of plant growth and development. Of the
three environmental variables studied, higher growth temperatures
resulted in the largest number of significant changes to the measured
variables. Reproductive capacity, growth rate, shoot biomass,
water use efficiency and chlorophyll content were all enhanced
by raising the growth temperature from 18 to 25 C. Doubling the
CO2 concentration enhanced the growth rate, shoot biomass
and water use efficiency and ameliorated some of the effects of
drought, including reproductive capacity, and biomass production,
but reduced flowering time, specific leaf area, and chlorophyll
content of both droughted and well-watered plants. Drought alone
reduced reproductive capacity, growth rate and above ground biomass
but significantly increased root biomass in all environments.
The agronomic effects resulting from a combined increase in growth
temperature, doubled CO2 concentration and mild drought
in this experiment were a shorter vegetative period and an increase
in biomass, but a fall in reproductive capacity.
Native grassland improvement on basaltic and granitic soils
in Uruguay. In Rangelands in a sustainable biosphere.
Proceedings of the Fifth International Rangeland Congress, Salt
Lake City, Utah, USA, 23-28 July, 1995. Volume 1: Contributed
presentations. Berretta, E. J.; Risso, D. F. <Editors> West,
N. E. Society for Range Management. 1996. p. 52-53.
Experiments in Uruguay on granite soils direct sown with Trifolium
repens cv. E. Zapican and Lotus corniculatus cv. San
Gabriel and on basalt soils direct sown with T. repens, L.
corniculatus and L. subbiflorus cv. El Rincon consistently
showed improvements of 50-100% in forage yield and increased forage
quality and range condition. The proportion of C4 grasses on the
rangelands decreased and the proportion of C3 grasses increased.
High frequency transformation and regeneration of transgenic
plants in the model legume Lotus japonicus. Stiller,
J.; Martirani, L.; Tuppale, S.; Chian RuJu; Chiurazzi, M.; Gresshoff,
P. M. Journal of Experimental Botany. 1997. 48:1357-1365.
The molecular analysis of plant genes involved in nodulation has
been slowed by the inability to produce high numbers of transgenic
legume lines. The high efficiency gene transfer and plant regeneration
systems of the model legume Lotus japonicus is described.
A collection of wild-type Agrobacterium rhizogenes strains
was tested for infectivity and the most virulent strains, 9402
and AR10, were selected for further use. Growth conditions for
plantlets, induction of hairy roots and nodulation of composite
plants were optimized for large-scale screening in Petri dishes.
A cluster of 3-10 nodules was regularly formed on transgenic hairy
roots 7-12 days after inoculation with the effective Rhizobium
loti strain NZP2235. There were no apparent morphological
differences between nodulation of hairy and wild-type roots. To
test the applicability of the hairy root system for the trapping
of symbiotic genes, transformation experiments with binary vectors
possessing a beta -glucuronidase (gus, uidA) or a luciferase (luc)
reporter driven by a cauliflower mosaic virus (CaMV) 35S promoter
were performed. The frequency of cotransfer of a binary T-DNA
with a root-inducing (Ri) T-DNA was 70%. Positive expression suggests
that gus and luc trap vectors can be used for gene tagging in
L. japonicus. To open the possibility of searching for
mutant phenotypes, a regeneration system has been developed enabling
the regeneration of large numbers of transgenic plants from hairy
root cultures in about 5-6 months. At the same time, the A.
tumefaciens hypocotyl transformation regeneration in L.
japonicus has been improved. This new version provides fertile
transgenic plants in about 4 months.
Genetically engineered plants producing opines alter their
biological environment. Oger, P.; Petit, A.; Dessaux, Y. Nature
Biotechnology. 1997. 15:369-372.
Little is known about the consequences of releasing genetically
engineered plants (GEP) into the environment. Indigenous soil
populations of bacteria were monitored around roots of transgenic
plants engineered to produce low-MW compounds that may be used
as growth substrates by rhizospheric bacteria. Lotus corniculatus
was transformed by Agrobacterium rhizogenes to produce
mannopine, nopaline or a combination of mannopine, nopaline and
cucumopine from roots. Root bacterial populations were sampled
after 14 weeks greenhouse growth in a real soil mixture. In all
experiments, the concentrations of total cultivable bacteria were
not significantly different in the rhizospheres of transformed
and control plants, whereas the concentration of bacterial utilizers
of a given opine were always much higher in transgenic plants.
This shows that GEP can alter their biological environment, and
that these alterations are both transgene-specific and target
population-specific. Therefore, assessment studies on the introduction
of a given transgene into a GEP will be valid on the given transgene.
Evidence of any transgene-associated biological effect will depend
on the determination of pertinent target populations, the identification
of which is a key step of such studies.
Transposon tagging in Lotus japonicus using the maize
elements Ac and Ds. In Biology of plant-microbe interactions.
In Proceedings of the 8th international symposium on molecular
plant-microbe interactions, Knoxville, Tennessee, USA, 14-19 July
1996. Pajuelo, E.; Schauser, L.; Thykjaer, T.; Larsen, K.; Stougaard,
J. <Editors> Stacey, G.; Mullin, B.; Gresshoff, P. M. International
Society for Molecular Plant-Microbe Interactions. 1996:381-386.
Preliminary research into tagging symbiotic genes in L. japonicus
using transposable elements from maize is reported. The element
Activator (Ac) was transferred into L. japonicus via
Agrobacterium tumefaciens mediated transformation and its
behaviour was scored in progeny from 123 independent transformants.
Excision activity was detected in progeny from 58% of the lines.
In 62% of these lines, a segregation of approximately 3:1 for
a dominant gene was detected. These results indicate that transposon
tagging in L. japonicus is feasible. Preliminary data from
Dissociation (Ds) show that it too can be mobilised in L. japonicus.
Initial screening on medium without reduced nitrogen identified
one or two symbiotic mutants tagged with Ac.
OAC Bright birdsfoot trefoil. Twamley, B. E.; Tomes, D.
T.; Bowley, S. R. Canadian Journal of Plant Science. 1997. 77:251-253.
OAC Bright is a birdsfoot trefoil (Lotus corniculatus)
cultivar developed by the Crop Science Department, University
of Guelph and registered in 1995. It was developed by within and
among half-sib progeny recurrent selection for seedling vigour
and seed yield in cv. Leo. OAC Bright has 2% higher seedling vigour
and 0.8% higher herbage yield than Leo, but similar maturity and
persistence.
Multi-cultivar legume-grass crops as a method of increasing
floristic diversity and feeding value of pasture swards. <Original>
Wieloodmianowe zasiewy motylkowo-trawiaste sposobem na zwiekszenie
roznorodnosci florystycznej i wartosci paszowej runi pastwiskowej.
Warda, M.; Cwintal, H.; Krzywiec, D. Zeszyty Problemowe Postepow
Nauk Rolniczych. 1996. 442:453-464.
In trials on chernozem and peat muck soils at Sosnowica, Trifolium
repens, Lotus corniculatus, Medicago lupulina and M. sativa
were sown in May 1994 in mixtures (50% legume) with 30% Lolium
perenne, 15% Phleum pratense and 5% Dactylis glomerata,
given NPK and grazed twice in 1994 and 4 times in 1995 by cows
and calves. Changes in the species composition of the swards are
reported. Seasonal changes in legume content were greater on chernozem
than on peat muck soil. By 1995, the proportions of all the legumes
except T. repens were low on peat muck soil and did not
exceed 30% on chernozem. L. perenne was dominant in most
cases. Averaged over soil types, mixtures with the 4 legumes as
listed yielded 5.13, 5.55, 4.38 and 4.52 t dry matter in 1994.
In 1995 the mixture with T. repens yielded most on both
soils, but average yields (9.28-9.71 t) did not differ significantly.
Herbage K, Ca and Mg contents differed more between soil types
than between mixtures.
Yield of a meadow oversown with Lotus corniculatus under
conditions of limited nitrogen fertilizer application. <Original>
Plonowanie laki podsianej komonica zwyczajna w warunkach ograniczonego
nawozenia azotowego. Grzegorczyk, S.; Olszewska, M. Zeszyty Problemowe
Postepow Nauk Rolniczych. 1996. 442:115-124.
In 1993, meadow swards dominated by Dactylis glomerata and
Bromus inermis were rotary cultivated, oversown with L.
corniculatus and given 80 kg P2O5 +
120 kg K2O + 0, 60 or 120 kg N/ha; N was applied at
each of 3 cuts. In 1994-95, dry matter yields of all the oversown
plots were lower than those of D. glomerata and B. inermis
given 250 kg N, but tended to increase with increasing N rate.
The percentage of L. corniculatus decreased and that of
the grasses increased with increasing N rates. Data on herbage
N, P, K, Mg and Ca content are given. Oversowing with L. corniculatus
was regarded as an effective way of improving the sward and reducing
use of N fertilizer.
Lotus corniculatus as a valuable component of
dry meadows in the Olsztyn lakeland. <Original> Komonica
zwyczajna jako cenny element lak gradowych na Pojezierzu Olsztynskim.
Grzegorczyk, S.; Benedycki, S.; Grabowski, K. Zeszyty Problemowe
Postepow Nauk Rolniczych. 1996. 442:105-114.
Twenty plant communities with a high percentage of L. corniculatus
were analysed in 1993-95; of these, 14 were classed as Lolio-Cynosuretum
and 6 as Arrhenatheretum elatioris. These were found on
soils with pH in the range 4.4-7.3 and 5.7-7.0, respectively,
with low P and K, moderate Mn, Fe, Cu and Zn and high Mg contents.
Leaves of L. corniculatus were rich in N, Ca and Mg but
deficient in P, Na, Zn and Mn.
Botanical and chemical composition of hay from cultivated meadows
on acid forest soils. <Original> Sklad botaniczny i
chemiczny siana z lak zagospodarowanych na kwasnych glebach polesnych.
Gajda, J. Zeszyty Problemowe Postepow Nauk Rolniczych. 1996. 442:81-87.
A mixture of 8 grasses and 3 legumes, with a cover crop of Lolium
multiflorum, was sown on very acid soil in 1983, with or without
high rates of lime. By 1987, Dactylis glomerata made up
59-78% by weight of the hay yield on limed plots. Because of this
and the poor vegetative cover, the meadow was resown with a mixture
of Phleum pratense, Festuca pratensis, Bromus inermis, Poa
pratensis, F. rubra, Lotus corniculatus and Trifolium hybridum
in 1989 with the same liming treatments. By 1994-95 the legumes
had disappeared. Arrhenatherum elatius and P. pratensis
were the dominant species on unlimed plots. P. pratensis
made up 30-51% of the hay yield on limed plots. The beneficial
effects of liming on the soil, the sward and the chemical composition
of the hay lasted for a considerable time.
Wavelength options for monitoring leghaemoglobin oxygenation
gradients in intact legume root nodules. Shimada, S.; Rousseau,
R.; Denison, R. F. Journal of Experimental Botany. 1997. 48:1251-1258.
Nodule oximetry, based on spectrophotometric measurements of leghaemoglobin
(Lb) oxygenation in intact nodules, is used to study legume nodule
physiology. Different wavelengths are compared for study of fractional
oxygenation of Lb (FOL). Changes in transmittance were monitored
simultaneously at 660 nm and either 560 or 580 nm as FOL was manipulated
by changing the O2 concentration around nodules of
Medicago sativa or Lotus corniculatus. Video microscopy
at 580 nm was used to generate two-dimensional maps of FOL gradients
in intact nodules. In general, all three wavelengths gave similar
results. Small discrepancies between 660 and 580 nm, sometimes
seen in nodules with high O2 permeability, may indicate
interference by the ferric Lb peak at 625 nm. A slightly longer
wavelength, for example 670 nm, might be preferable. No significant
discrepancies among wavelengths were seen in nodules whose O2
permeability had been reduced by a 48 h exposure to 10 mM nitrate.
Minor gradients in FOL were seen in nodules of M. sativa and
Trifolium repens under air and steeper gradients could be
induced by various treatments. The existence of these gradients
indicates at least some restriction of long-range O2
diffusion within the infected zone. The FOL maps do not have enough
spatial resolution to measure gradients within infected cells.
Leucocyanidin reductase activity and accumulation of proanthocyanidins
in developing legume tissues. Skadhauge, B.; Gruber, M. Y.;
Thomsen, K. K.; Wettstein, D. von. American Journal of Botany.
1997. 84:494-503.
Proanthocyanidin (PA) and anthocyanin accumulation and location
in developing leaves, flowers, and seeds of the legumes Medicago
sativa, Lotus japonicus, Lotus uliginosus, Hedysarum sulfurescens
(H. sulphurescens), and Robinia pseudacacia
(R. pseudoacacia) were investigated by quantitative
measurements and by histological analysis after staining with
1% vanillin/HCl, butanol/HCl, or 50% HCl. M. sativa leaves
and flowers, L. japonicus leaves, and R. pseudoacacia
flowers do not contain PAs, but seeds of all investigated species
contain PAs. Anthocyanins are absent in the seed coats of all
five species and in leaves of L. japonicus. PA content
generally increases as a function of development in leaves, but
declines in flowers. With the exception of H. sulfurescens,
flower PAs are synthesized in the parenchyma cells of the standard
petal, while anthocyanins are located in the neighbouring epidermal
cells. Leucocyanidin reductase (LCR) catalyses the conversion
of 2,3-trans-3,4-cis-leucocyanidin to (+)-catechin and is the
first enzyme in the PA-specific pathway. LCR activity was only
detected in PA-containing tissues and generally declined during
tissue development.
Phenolic compounds and characterization of low taxonomic levels
in the plant kingdom. <Original> Les composes phenoliques
et la caractersiation des niveaux taxonomiques inferieurs du monde
vegetal. Jay, M.; Reynaud, J.; Raymond, O.; Grossi, C. Acta Botanica
Gallica. 1996. 143:481-491.
Chemical markers, such as phenolic compounds, have been extensively
used in botanical chemosystematic studies; these have largely
concerned the high taxonomic levels: order, family, genus. As
a consequence of new, more sensitive and automatic analytical
procedures, it is now possible to study the metabolic (phenolic)
profile of individual genotypes. Three examples are used to illustrate
this new approach: the subspecific composition of the Dactylis
glomerata complex, Rosa x hybrida (botanical origins
of Bengal, Bourbon and Noisette roses), infraspecific differences
in Lotus corniculatus (diploids and tetraploids).
"Animal friendly" nutrition - designer plants?.
West, D. M. Veterinary Continuing Education, Massey University.
1996. No. 170:59-65. Sheep Sessions - Second Pan Pacific Veterinary
Conference, Christchurch, New Zealand, 23-28 June 1996.
Veterinary problems resulting from pasture feeding systems are
reviewed with particular reference to those in New Zealand. These
include the limitations of pasture in providing animals with requirements
for minerals such as magnesium, trace elements such as copper,
cobalt and selenium, and energy, especially for cows in early
lactation. The significant levels of various toxins which affect
the health and performance of some grazing livestock are also
discussed.
Biochemical composition of the green matter and yield in different
varieties of birdsfoot trefoil. Nikolaichuk, V. I.; Yalovskaya,
A. I. Fiziologiya i Biokhimiya Kul'turnykh Rastenii. 1997. 29:209-214.
Content of dry matter, proteins, cellulose, carotene and ascorbic
acid in the green matter at various stages, together with green
matter yield, was determined in 20 varieties of Lotus corniculatus
in the second to fourth years of growth (1989-92). In all, 7 varieties
with high fodder quality were identified: Maikopskii, Leo, Smolenskii,
Listan, Eddei and the local forms MF1 and MF2.
Construction of a Lotus japonicus late nodulin expressed
sequence tag library and identification of novel nodule-specific
genes. Szczyglowski, K.; Hamburger, D.; Kapranov, P.; Bruijn,
F. J. de. Plant Physiology. 1997. 114:1335-1346.
A range of novel expressed sequence tags (ESTs) associated with
late developmental events during nodule organogenesis in the legume
Lotus japonicus were identified using mRNA differential
display; 110 differentially displayed polymerase chain reaction
products were cloned and analysed. Of 88 unique cDNAs obtained,
22 shared significant homology to DNA/protein sequences in the
respective databases. This group comprises, among others, a nodule-specific
homologue of protein phosphatase 2C, a peptide transporter protein,
and a nodule-specific form of cytochrome P450 which were sequenced
and full-copy or almost full-copy cDNA sequences have been submitted
to GenBank under the accession numbers AF000402, AF000392 and
AF000403, respectively. RNA gel-blot analysis of 16 differentially
displayed ESTs confirmed their nodule-specific expression pattern.
The kinetics of mRNA accumulation of the majority of the ESTs
analysed were found to resemble the expression pattern observed
for the L. japonicus leghaemoglobin gene. These results
indicate that the newly isolated molecular markers correspond
to genes induced during late developmental stages of L. japonicus
nodule organogenesis and provide important, novel tools for the
study of nodulation.
Germplasm exploration in the north Caucasus Mountains, Russia
to collect forage legume species for forage crop improvement.
Green, S. L.; Graves, W. Dryland Pasture, Forage & Range Network
News. 1996. No. 12:21-22.
A list is given of the 579 accessions obtained on a collecting
mission during August-September 1995 to 120 sites in the north
Caucasus. Accessions included 75 of Lotus corniculatus,
55 of Dactylis glomerata and 45 of Trifolium pratense.
Differential expression of a gamma -zein gene in Medicago
sativa, Lotus corniculatus and Nicotiana tabacum.
Bellucci, M.; Lazzari, B.; Viotti, A.; Arcioni, S. Plant Science
(Limerick). 1997. 127:161-169.
With the aim of increasing the content of sulfur amino acids (SAAs)
in the aerial part of the plants, N. tabacum and two leguminous
species, M. sativa and L. corniculatus, were transformed
with a maize gamma -zein gene (G1L) coding for a SAAs-rich protein.
Gene fusions were constructed using the constitutive CaMV 35S
promoter and the light-regulated ribulose-bisphosphate carboxylase
small subunit (rbcS) promoter from tobacco. The constructs were
introduced into plants by Agrobacterium-mediated gene transfer.
All the transformants produced the G1L RNA (two differently sized
transcripts were detected) and no relevant differences were found
between the two promoters. Despite the presence of the G1L message,
the gamma -zein was found only in tobacco plants (up to 0.05%
of the alcohol soluble proteins). Post-transcriptional mechanisms
seemed to inhibit protein accumulation. The low level of G1L RNA
in the transformed plants was probably the main factor that limited
the production of gamma -zein protein.
Susceptiblity of 'Skyline' honeylocust to cankers caused by
Nectria cinnabarina influenced by nursery field management
system. Calkins, J. B.; Swanson, B. T. Journal of Environmental
Horticulture. 1997. 15:6-11.
The influence of five nursery field management treatments (soil
cultivation, oxadiazon application, Lotus corniculatus
companion crop, winter rye + Lolium perenne + Festuca
rubra cover crop) on the incidence of stem cankers caused
by Nectria cinnabarina on Gleditsia triacanthos
var. inermis cv. Skyline was monitored in Minnesota. Although
considered a stress related disease, field management treatments
that reduced tree vigour decreased susceptibility to attack by
N. cinnabarina while treatments which promoted vigorous
growth increased susceptibility. The observed vulnerability of
G. triacanthos trees to N. cinnabarina may be related
to plant cold hardiness and subsequent winter injury to root and
crown tissue as affected by nursery field management treatment.
Moisture stress late in the growing season, resulting from root
injury during the previous winter, mechanical root injury from
cultivation, and high summer soil temperatures may have increased
susceptibility to N. cinnabarina in G. triacanthos
grown in bare soil field production systems. Moisture stress in
late summer may not be reflected in plant growth, but may increase
the susceptibility of G. triacanthos trees to attack by
N. cinnabarina.
Management of birdsfoot trefoil (Lotus corniculatus L.)
pastures for productivity and persistence. Bologna, J. J.;
Rowarth, J. S.; Fraser, T. J.; Hill, G. D. In Proceedings
Annual Conference - Agronomy Society of New Zealand. 1996. 26:17-21.
The effects of contrasting grazing treatments on herbage and seed
yield, and seedling recruitment of a birdsfoot trefoil (Lotus
corniculatus) cv. Grasslands Goldie pasture were evaluated
at AgResearch Lincoln, New Zealand, on a Pallic soil (Wakanui
silt loam) over the period October 1994 to March 1996. Cutting
every two weeks reduced plant density and herbage yield. The highest
seed yield was 651 kg/ha from pastures closed in November. It
was concluded that intervals between cuttings should not be shorter
than 4 weeks for the original plants to survive under grazing;
this grazing interval is also consistent with maximum seedling
recruitment following a November closing (422 seedlings/m2).
It is suggested that production and persistence may be increased
by seasonal adjustments in the frequency of cutting.
CO2 effects on the water budget of grassland microcosm
communities. Field, C. B.; Lund, C. P.; Chiariello, N. R.;
Mortimer, B. E. Global Change Biology. 1997. 3:197-206.
Experimental grassland ecosystems, in microcosms 0.2 m in diameter
and with a 0.95 m soil column, varied in their responses to elevated
partial pressure of CO2 (pCO2) and altered
moisture inputs. Ecosystems on moderately fertile sandstone soil
and with a typical mix of moderately fast-growing sandstone species
(Avena barbata, Bromus hordeaceus, Hemizonia congesta subsp.
luzulifolia, Lotus wrangelianus and Nassella pulchra),
responded to elevated pCO2 with decreases in mid-season
evapotranspiration of nearly 50%. This pattern reversed at the
end of the growing season, and sandstone ecosystems under elevated
pCO2 continued active transpiration farther into the
summer drought. The sandstone ecosystems appeared to convert mid-season
water conservation into increased late-season growth. Effects
of increased pCO2 on ecosystem evapotranspiration were
much smaller in ecosystems with very infertile serpentine soil
and a diverse mixture of slow-growing serpentine species (Plantago
erecta, Lasthenia californica, Vulpia microstachys, and the
same species as on the sandstone soil, except A. barbata).
Proanthocyanidins from Lotus pedunculatus. Foo,
L. Y.; Lu, Y.; McNabb, W. C.; Waghorn, G.; Ulyatt, M. J. Phytochemistry.
1997. 45:1689-1696.
A range of flavanols and proanthocyanidin dimers were isolated
and identified from leaves of Lotus pedunculatus (L.
uliginosus). The more abundant polymeric proanthocyanidins
were also isolated and their chemical constitution studied by
13C NMR and by acid-catalysed degradation in the presence of excess
phloroglucinol. These results showed the polymers to be highly
heterogeneous, with catechin, epicatechin, gallocatechin and epigallocatechin
all being constituent components of both the extenders as well
as the terminating units. Epigallocatechin was the most abundant
extension unit and catechin the more common terminating flavonoid.
The average molecular size of the polymers was estimated by 13C
NMR to be ca eight flavonoid units and there was spectroscopic
and chemical evidence to indicate that a small portion of these
units were glycosylated.
Increase in forage yield in narrowleaf birdsfoot trefoil (Lotus
tenuis Waldst & Kit ex Willd) in a permanent pasture with
foliar applied gibberellic acid (GA3), and phosphorus.
Clua, A. A.; Gimenez, D. O.; Fernandez, L. V. Plant Growth Regulation.
1997. 21:223-228.
In field experiments in La Plata, Argentina, plots in permanent
legume/grass pasture were given foliar application of 0 or 50
mg GA/litre in 1994 and foliar application of 0, 25 or 50 mg GA
with or without 8 kg P/ha in 1995. In 1994 legumes made up 56%
of the pasture, of which 99% was L. tenuis, while in 1995
the legume fraction was 39% with a similar percentage of L.
tenuis. In 1994 GA significantly increased L. tenuis
dry matter (DML) but not the dry matter of the grass fraction
(DMG), and in consequence the total dry matter of the pasture
(TDMP) was increased. In 1995 all GA treatments and their combinations
with P increased DML but not DMG, with 25 mg GA + P being most
effective with a 151% increase in DML. Consequently TDMP was significantly
increased due to a larger proportion of L. tenuis in the
forage yield. This increase was achieved due to a greater length
and diameter of L. tenuis branches, with a related modification
in leaf:stem ratio. Moreover, GA treatments reduced L. tenuis
flower number. P treatment alone increased DML. The 50 mg GA treatments,
with or without P, increased acid detergent fibre and neutral
detergent fibre percentages and decreased crude protein percentage
of the forage compared with the control, while the total crude
protein yield was increased in all GA and GA + P treatments. GA
and P increased the competitiveness of L. tenuis for light,
on account of a faster growth rate than the grasses, with L.
tenuis stems reaching the top of the pasture canopy faster.
Analysis of adaptation of grass/legume mixtures to Italian
alpine and subalpine zones through an additive main effects and
multiplicative interaction model. Annicchiarico, P.; Bozzo,
F.; Parente, G.; Gusmeroli, F.; Mair, V.; Marguerettaz, O.; Orlandi,
D. In: Grass and forage science : the Journal of the British
Grassland Society Dec 1995. 50:405-413.
Productivity of Lotus corniculatus L. (bird's-foot trefoil)
in the UK when grown under low-input conditions as spaced plants,
monoculture swards or mixed swards. Bullard, M.J.; Crawford,
T.J. In: Grass and forage science : the Journal of the
British Grassland Society. 1995. 50:439-446.
Post-burn recovery in the flooding Pampa: impact of an invasive
legume Laterra, P. In: Journal of range management.
1997. 50:274-277.
Winter burning of Paspalum quadrifarium Lam. stands ("pajonales")
promotes colonization of denuded spaces by several alien species.
Lotus tenuis Waldst et Kit. ("lotus"), a recent
invader of the region, is able to reach very high densities between
the resprouting bunches of the dominant species. Results of a
removal experiment performed to evaluate the impact of natural
establishment of lotus on post-born colonization of pajonal stands
are reported. Seedlings of lotus were removed shortly after their
emergence between burned bunches of P quadrifarium. Eighty
days after burning, approximately 30% of the soil surface remained
uncovered within removal plots, whereas canopy cover was complete
within controls. Furthermore, final (137 days post-burn) total
aboveground biomass was 2.7 times higher in control than in removal
plots. Removal of lotus significantly (P<0.05) increased the
cover of an annual native grass (Phalaris angusta Nees,
ex Trin.) and the final biomass of an alien thistle (Carduus
acanthoides L). A spatial association analysis provided additional
evidence about the negative impact of lotus on colonization success
of C. acanthoides. Weed colonization may be reduced, if
not prevented, by managing the colonization processes of other
new and useful invaders.
Influence of phosphorus nutrition on mycorrhizal growth response
and morphology of mycorrhizae in Lotus tenuis. Mendoza,
R.E. ; Pagani, E.A. In: Journal of plant nutrition. 1997.
20:625-639.
The effect of several rates of phosphorus (P) supply on the formation
of mycorrhizae by indigenous fungi in Lotus tenuis was
studied. A greenhouse experiment was conducted for 45 days on
a P-deficient soil fertilized with 0-160 micrograms P g-1 soil.
The most prevailing VAM fungus that infected roots was Glomus
sp, resembling Glomus fasciculatum. Adding P to the soil
influenced the mycorrhizal growth response, the extent of the
mycorrhizal infection, and the morphological characteristics of
the mycorrhizal colonization in roots Non-mycorrhizal plants required
1.5 times more added P to obtain the same yield as mycorrhizal
plants. Nevertheless, the relationship between the P concentration
in shoots and the dry weight of shoots was the same for both mycorrhizal
and non-mycorrhizal plants suggesting that differences in growth
reflect differences in the uptake of P rather than its utilization
within the plant. The percent of root length infected (HC) and
the fraction of infected roots containing arbuscules (AC) initially
increased at low levels of added P, and then with further additions,
they decreased. The number of entry points per unit of root length
infected decreased with increasing P concentration in the shoots.
The ratio between the number of entry points and hyphal and arbuscule
density decreased at low P and then increased with increasing
added P. Thus, the morphology of the mycorrhizal was altered by
P nutrition. It was concluded that at the lower levels of added
P, the low P soil status inhibited both the spread of the fungus
within the root and the growth of the roots.
Phytochemical survey of Lotus tenuis Waldst. & Kit.
Wagner, M.L.; Strittmatter, C.D.; Kade, M.; Rivero, M.; Ricco,
R.A.; Gurni, A.A. Phyton. 1996. v. 58, p. 141-146.
Down-regulation of sucrose synthase expression and activity
in transgenic hairy roots of Lotus japonicus. Skot,
L.; Gordon, A. J.; Timms, E.; James, C. L.; Webb, K. J.; Mizen,
S. Symbiosis (Rehovot) 1997. 22:241-254.
Sucrose synthase is central to carbon metabolism in roots and
nodules of legumes. In order to analyse its role antisense RNA
strategies were used to down-regulate its expression in the model
legume Lotus japonicus. In contrast to other legumes
the sucrose synthase gene from Lotus was expressed highly
not only in nodules, but also in roots. This enabled the use of
transgenic hairy roots to evaluate the potential of the antisense
RNA strategy. The sucrose synthase sense message was drastically
reduced in 4 out of 5 antisense sucrose synthase hairy root lines.
Sucrose synthase protein levels were significantly reduced, and
sucrose synthase enzyme activities declined to between 20% and
25% of the controls. By contrast, activities of UDPglucose pyrophosphorylase,
fructokinase, glucokinase and acid invertase remained unchanged,
while unexpectedly, alkaline invertase activity declined in the
antisense sucrose synthase lines. The significantly higher fresh
weight of the control cultures compared to the antisense hairy
roots observed after 14 days of growth, suggest that the changes
in enzyme activities affected the growth rate. Overall, this work
demonstrates that the antisense RNA strategy can be used successfully
in L. japonicus to alter gene expression.
Gene targeting approaches using positive-negative selection
and large flanking regions. Thykjaer, T.; Finnemann, J.; Schauser,
L.; Christensen, L.; Poulsen, C ; Stougaard, J Plant Molecular
Biology. 1997 35:523-530.
Strategies aimed at improving the frequency of detectable recombination
in plants by increasing the efficiency of selecting double-recombinants
in transgenic calluses are reported. Gene targeting was approached
on the Gln1 and the Pzf loci of Lotus japonicus, using
Agrobacterium tumefaciens T-DNA replacement vectors. Large
flanking regions (GenBank/EMBL/DDBJ accession number Y09539),
up to 22.9 kb, surrounding a positive selection marker were presented
as substrates for homologous recombination. For easier detection
of putative recombinants the negative selectable marker cytosine
deaminase was inserted at the outside borders of the flanking
regions offered for cross-over. A combination of positive and
negative selection allowing double-recombinants to grow, while
counter-selecting random insertions, was used to select putative
targeting events. The more than 1000-fold enrichment observed
with replacement vectors designed to minimize gene silencing demonstrated
the efficiency of the negative selection. Using five different
replacement vectors an estimated total of 18 974 transformation
events were taken through the positive-negative selection procedure
and 185 resistant calluses obtained. Targeting events could not
be verified in the survivors by PCR screening and Southern blot
analysis. With this approach the frequency of detectable gene
targeting in L. japonicus was below 5.3 x 10-5, despite
the large flanking sequences offered for recombination.
Differential modification of flavonoid and isoflavonoid biosynthesis
with an antisense chalcone synthase construct in transgenic Lotus
corniculatus. Colliver, S. P.; Morris, P.; Robbins, M.
P. Plant Molecular Biology. 1997. 35:509-522.
Three clonal genotypes of Lotus corniculatus (bird's foot
trefoil) were transformed with an antisense chalcone synthase
(naringenin-chalcone synthase) (CHS) gene construct made using
a stress induced CHS 17 cDNA from Phaseolus vulgaris under
the control of the constitutive CaMV 35S promoter and Nos terminator
via Agrobacterium rhizogenes. After initial screening,
ten antisense and five control co-transformation events from each
recipient clonal genotype were analysed. After elicitation with
glutathione, the level of tannin accumulation increased in a number
of antisense root cultures derived from the low (S33) and moderate
(S50) tannin recipient genotypes. Six antisense and four control
transformed lines from genotype S50 were selected for more detailed
study. The antisense CHS construct was integrated into the genome,
with a copy number ranging from 1 to 5 and antisense orientation
was confirmed by PCR. In transformed root cultures, increased
CHS transcript levels were noted in a number of antisense lines.
Biochemical analyses of glutathione-elicited root cultures indicated
a significant increase in tannin accumulation in antisense CHS
lines and mean vestitol levels were reduced. These results show
that the introduction of a heterologous antisense chalcone synthase
construct into L. corniculatus resulted in an unpredicted
molecular and biochemical phenotype. Such findings are discussed
in relation to manipulation of this complex multigene family.
Expression of an Antirrhinum dihydroflavonol reductase
gene results in changes in condensed tannin structure and accumulation
in root cultures of Lotus corniculatus (bird's foot trefoil).
Bavage, A. D.; Davies, I. G.; Robbins, M. P.; Morris, P. Plant
Molecular Biology. 1997. 35:.443-458.
Condensed tannins (proanthocyanidins) are an important factor
in the nutritive and dietary quality of many forage crops. Here,
experiments aimed at altering the levels and monomer composition
of condensed tannins (CTs) in 'hairy root' cultures of Lotus
corniculatus (bird's foot trefoil) using genetic manipulation
are reported. An Antirrhinum majus dihydroflavonol
reductase (dihydrokaempferol 4-reductase) (DFR) cDNA was expressed
in sense in L. corniculatus and CT levels in transgenic
root cultures were analysed. Two co-transformed lines were noted
with decreased CT content relative to controls and these levels
were comparable with antisense-DFR phenotypes. In ADFR10, a co-transformed
line with the highest CT levels, CT structure was altered in a
manner consistent with the substrate specificity of the introduced
gene; that is an increase in pro-pelargonidin monomers noted after
hydrolysis of CTs. RT-PCR confirmed the expression of endogenous
DFR gene(s) in both putatively co-suppressed lines and also in
ADFR10 Analysis of selected root culture lines indicated that
the monomer composition of CTs did not change during growth and
development but that levels of CTs varied in a regulated manner.
Nucleotide sequence data have been submitted to the GenBank/EMBL/DDBJ
databases under accession number X97576 (L. corniculatus
DFR fragment).
Two ineffective-nodulating mutants of Lotus japonicus
- different phenotypes caused by the blockage of endocytotic bacterial
release and nodule maturation. Imaizumi-Anraku, H.; Kawaguchi,
M.; Koiwa, H.; Akao, S.; Syono, K. Plant and Cell Physiology.
1997. 38:871-881.
Mutants defective in nodule development and nitrogen fixation
of L japonicus B129 'Gifu' were obtained by induced mutagenesis
with EMS (ethyl methanesulfonate). Using a symbiont of L. japonicus
(Rhizobium loti JRL501), 17 000 M2 seeds were screened
for plants affected in their symbiotic phenotype, resulting in
the successful isolation of eleven stable mutants, two of which
were ineffective nodulating mutants. Reciprocal crossing between
wild type Gifu and these mutants indicated that their phenotypes
are under monogenic and recessive control. Furthermore, tests
for allelism with these mutants showed that the mutated genes
are non-allelic. Ultrastructural analysis revealed that these
mutants were inhibited at different stages of nodule development
and maturation. Based on histological characteristics of the nodules,
the two ineffective nodulating mutants were named alb1 (aberrant
localization of bacteria inside nodule) and fen1 (failure in enlargement
of infected cells). In the nodules of alb1, most of the bacteria
failed to invade the cytoplasm of cortical cells and were tightly
confined inside infection threads or localized in intercellular
spaces of nodules. Following prolonged inoculation, the alb1 mutant
also formed pale-pink coloured nodules with a low frequency, in
which bacteria differentiated into bacteroid and fixed nitrogen
normally Although the infected cells in the nodules of the fen1
mutant contained numerous differentiated bacteroids, they failed
to enlarge by cell expansion and showed a low activity of nitrogen
fixation.
Chloroplast-DNA variation in the genus Lotus (Fabaceae)
and further evidence regarding the maternal parentage of Lotus
corniculatus L. Gauthier, P.; Lumaret, R.; Bedecarrats,
A. Theoretical and Applied Genetics. 1997. 95:629-636.
To resolve the maternal parentage of the tetraploid Lotus
corniculatus, restriction-site variation of chloroplast DNA
(ctDNA) was studied in several accessions of that species, in
the four putative parental diploid species, L. tenuis, L. alpinus,
L. japonicus and L. uliginosus, and in four phylogenetically
more distant diploid species, L. hispidus, L. edulis, L. ornithopodoides
and Tetragonolobus maritimus var siliquosus.
Evidence of ctDNA maternal inheritance was obtained by using reciprocal
controlled crosses between plants of L. corniculatus and
natural tetraploid individuals of L. alpinus showing very
distinct restriction patterns. Interspecific ctDNA variation in
the eight Lotus species and T. siliquosus was analysed
by comparing ctDNA fragment patterns produced by five restriction
endonucleases and totalling 304 distinct fragments. Genetic differentiation
in ctDNA was very high between the L. corniculatus group
and L. hispidus on the one hand, and the three other species
on the other hand. Sixteen restriction-site mutations and eight
length polymorphisms were identified among the five species of
the L. corniculatus group and L. hispidus, Lotus uliginosus,
L. alpinus and L. japonicus showed at least six
DNA changes with regard to the molecule of L. corniculatus.
Accordingly, these species should be excluded as maternal progenitors
of L. corniculatus. Conversely, the ctDNA of L. tenuis
differed from that of L. corniculatus by only two small-length
mutations. As also suggested previously from an analysis of several
nuclear markers, the results reported here show decisively that
L. tenius may be considered as the most probable maternal
ancestor of L. corniculatus.
Organization and expression of genes in the genomic region
surrounding the glutamine synthetase gene Gln1 from Lotus japonicus.
Thykjaer, T.; Danielsen, D.; She, Q.; Stougaard, J. Molecular
and General Genetics. 1997. 255:628-636.
Nucleotide sequences and derived gene organization of the
region flanking the glutamine synthetase (glutamate-ammonia ligase)
(GS) gene were studied in L. japonicus. Two functional
genes with the same transcriptional orientation were identified
within the 23.3 kb genomic region analysed. The LjGln1 gene encodes
a cytosolic GS and LjKrm (kinesin repeat motif) encodes a polypeptide
with similarity to a repeated motif present in the microtubule-associated
kinesin light chain protein from Drosophila melanogaster and rats.
Transcripts of LjGln1 are found primarily in roots and root nodules,
whilst transcripts of Krm are found in roots, root nodules and
leaves. In the region between Gln1 and Krm, the presence of a
third gene, Pge1, was suggested by analysis with the Grail exon
recognition program. Upstream of Gln1, a segment carrying 2 apparently
non-functional, fragmented copia-like retroelements, dRtp1 and
dRtp2, were identified. Sequence similarity to reverse transcriptase-and
RNaseH-coding regions of the maize Hopscotch element defined the
defective retroelements dRtp1 and dRtp2 within this segment. Terminal
repeats were not found but 3 different sets of short direct repeats
are located adjacent to the dRtp1 element. These 3 genes and the
incomplete retroelements occupy most of the analysed DNA, leaving
approximately one-fifth of the chromosome fragment without recognisable
genome constituents.
Studies to determine the best harvesting date for lucerne (Medicago
sativa), birdsfoot trefoil (Lotus corniculatus) and
sainfoin (Onobrychis viciifolia) based on maturation. <Original>
Hibridiniu liucernu, paprastuju garzdeniu ir sejamuju esparcetu
brendimo tyrimai nuemimo laikui nustatyti Slepetys, J. 1995.
No. 49:202-215.
Identifying suitable temperate forage legume species for saline
areas. Rogers, M. E.; Noble, C. L.; Pederick, R. J. Australian
Journal of Experimental Agriculture. 1997. 37:639-645.
The salt tolerance of 29 lines of annual and perennial forage
legume species was evaluated in 4 separate experiments over 0-100
mol NaCl/m3 in the greenhouse with the aim of identifying genetic
material that is more salt tolerant than the more traditionally
grown forage legume species. Several species or lines showed potential
as salt-tolerant germplasm including Trifolium tomentosum,
2 lines of T. squamosum and T. alexandrinum cv.
Mescani and Wardan which were all more salt tolerant than T.
subterraneum. Two lines of Lotus tenuis and 1 line
of L. corniculatus were also relatively salt tolerant.
Some of this material had never been assessed before under saline
conditions. In contrast, several other species (T. arvense,
T. vesiculosum, T angustifolium and T. pratense) were
found to be extremely salt sensitive and/or produced very small
amounts of dry matter over all NaCl concentrations.
Effect of cutting height and cutting interval on rhizome development,
herbage production and herbage quality of Lotus pedunculatus
cv Grasslands Maku. Harris, C. A.; Blumenthal, M. J.; Kelman,
W. M.; McDonald, L. Australian Journal of Experimental
Agriculture. 1997. 37:631-637.
A study was conducted to determine the influence of 3 defoliation
intervals (4, 8 and 12 weeks), at 3 harvest heights (2, 6 and
12 cm) on the rhizome development, herbage production and herbage
quality of Lotus pedunculatus cv. Grasslands Maku. An interaction
between cutting height and cutting interval was measured for both
rhizome number and length. As cutting interval became more frequent,
cutting height was more critical, with cutting to 2 cm every 4
weeks producing fewer and shorter rhizomes. Rhizome production
increased with increased cutting height and frequent cutting intervals
reduced rhizome production. The impact of severe defoliation was
greatest during late autumn and winter, when peak rhizome expansion
occurred. Although lenient cutting treatments encouraged rhizome
development and production it was at the expense of herbage production,
with longer cutting intervals and increasing cutting heights resulting
in less total herbage and lotus production. Increased rhizome
production was also associated with lower in vitro digestibility,
lower nitrogen concentration and higher condensed tannin concentration
of the lotus herbage. If long rotations are required to maintain
a persistent and competitive lotus sward in temperate and subtropical
pasture systems, then L. pedunculatus cv Grasslands Maku
is unlikely to play a major role in intensive grazing systems
in eastern Australia. This paper concludes with a discussion of
the possible use of strategic grazing practices of Grasslands
Maku swards to achieve a balance between rhizome production and
herbage production.
Evolution of natural and sown pastures, during the vegetative
period, on soil reclaimed after a landslide. <Original>
Evolutia pajistii naturale si a celei semanate, in timpul unei
perioade de vegetatie, pe un teren alunecat si amenajat.
<Document Title> 125 de ani 1869-1994. Lucrarile sesiunii
stiintifice "Prezent si perspectiva in horticultura".
20-21.10.1994. Budiu, V.; Ardelean, M.; Ropan, G. <Editors>
Muntean, L. S.; Miresan, E.; Rusu, M.; Budiu, V.; Marghitas, L.;
Cozma, V. 1994. p.303-312.
In 1979-82 in the Chinteni Valley, previously limed unproductive
land degraded by landslides and erosion was sown with a pure stand
of Lolium perenne or a mixture of (a) Dactylis glomerata
+ L. perenne + Medicago sativa, (b) Phleum pratense
+ Lotus corniculatus + Trifolium repens or
(c) D. glomerata + P. pratense + Onobrychis viciifolia
and no NPK or 3 applications of 60 kg N/ha, 120 kg N + 3 applications
of 60 kg P2O5/ha or 120 kg N + 3 applications of 60 kg P2O5 +
60 kg K2O/ha were applied; 3 harvests/year were taken. In the
mixtures, the grasses became dominant. With L. perenne
maximum content occurred in the first harvest and in the mixtures
in the third harvest. Maximum legume content occurred in the second
harvest and weed content in the third harvest (except in the natural
pasture). In the natural pasture the highest grass content occurred
with NPK, highest legume content with NP and highest weed content
with N. The highest L. perenne content occurred with N
and weed content with NP or NPK. In (a) D. glomerata content
was highest with 60 kg N/ha and legume content with no NPK. In
(b) P pratense content was highest with NP, the weed content
was low in all treatments and other grass species constituted
76-91% with NPK. In (c) D. glomerata constituted 85-92%
of the mixture with NP and weed content was highest with no NPK
(23-38%).
Contributions to the improvement of degraded permanent pasture
on the silvosteppe of Moldova with fertilizers, oversowing and
radical rehabilitation. <Original> Contributii la imbunatatirea
pajistilor permanente degradate, din silvostepa Moldovei, prin
fertilizare, suprainsamantare si refacere radicala. <Document
Title> 125 de ani 1869-1994. Lucrarile sesiunii stiintifice
"Tehnologii moderne in cultura plantelor de camp". 20-21.10.
1994. Iacob, T.; Dumitrescu, N.; Vantu, V.; Samuil, C. <Editors>
Muntean, S.; Miresan, E.; Rusu, M.; Budiu, V.; Marghitas, L.;
Cozma, V. 1994. p.275-284.
In 1986-93 at Iasi a degraded permanent pasture was oversown or
resown with Bromus inermis, Dactylis glomerata, Onobrychis
viciifolia and Lotus corniculatus and NPK + farmyard
manure was applied. The land was prepared for resowing using a
rotary seeder, chisel plough or discing Dry matter yields were
2.9 t/ha in the untreated control and increased by 72-190% with
NPK + farmyard manure, 65-131% with oversowing and 116-226% with
resowing + fertilizers.
Allelopathic effects on germination percentage in some legumes
and tall fescue (Festuca arundinacea Schreb.). <Original>
Alelopaticke ovlivneni klicivosti vybranych druhu jetelovin a
kostravy rakosovite (Festuca arundinacea Schreb.). Smolikova,
M.; Bartosova, L Rostlinna Vyroba 1997 43:425-429
Red clover (Trifolium pratense cv. Vesna), lucerne (Medicago
sativa cv Zuzana) and birdsfoot trefoil (Lotus corniculatus
cv. Lostar) seeds were sterilized and sown in simple mixtures
with sterilized tall fescue (F. arundinacea cv. Kora) seeds
in Petri dishes containing distilled water. The seeds were arranged
in rows or in a checkerboard pattern with a total of either 60
or 100 seeds/dish. Germination was evaluated for 7 days. The species
were also germinated separately as controls There were no significant
differences in germination between seed mixtures and the controls.
Sowing density and seed geometry had no definite effect on germination.
Birdsfoot trefoil and tall fescue were considered most likely
to have high allelopathic potential.
Establishment of perennial legume species in drought-prone,
North and South Island sites. Douglas, G. B.; Willis, B. J.;
Pryor, H. N.; Foote, A. G.; Trainor, K D. Proceedings of the New
Zealand Grassland Association. 1996. 58:253-257.
The establishment from seed of 8 perennial legumes was investigated
in 3 trials in drought-prone regions of New Zealand. Two trials,
in central Hawke's Bay (North Island), aimed to determine the
extent of establishment of 6 test species (Astragalus cicer,
Coronilla varia, Dorycnium hirsutum, Dorycnium pentaphyllum, Lotus
corniculatus, Lotus tenuis) and 2 standard species (Medicago
sativa, Trifolium repens). The third trial, in Central Otago
(South Island), aimed to identify the most effective strain of
Rhizobium loti for nodulating D. hirsutum in the
field. In Hawke's Bay, establishment of all species was satisfactory.
Seedling emergence ranged from 0.2% (T. repens) to 25%
(A. cicer, C. varia, D. hirsutum), but emergence levels
for all species varied between trials. Herbage yields of A.
cicer (4 t DM/ha), C. varia (3 t DM/ha) and L. tenuis
(3.7 t DM/ha) were relatively high, and they could have potential
as forages. Inoculation of seed of D. hirsutum with R.
loti strain ICC211 resulted in 60% of seedlings being nodulated,
compared with 25% where strain ICC224 was used. Foliage weights
of all plants inoculated with strain ICC211 (154 mg) were higher
than those inoculated with strain ICC224 (52 mg). Strain ICC211
is recommended for inoculating D. hirsutum.
Intraspecific biodiversity in grasslands. I. A study of local
variations in cyanogenic polymorphism in Lotus corniculatus
L (Fabaceae). In Biodiversity and management of grassland
ecosystems, Metz, France, 8-10 June 1995. <Original>
Biodiversite intraspecifique dans les formations prairiales I-Recherche
des causes de variation, a l'echelle locale, du polymorphisme
cyanogenique chez Lotus corniculatus L. (Fabacees). Louveaux,
A.; Blaise, S.; Cartier, D.; Dreuillaux, J. M. <Editors>
Muller, S. Acta Botanica Gallica. 1996. 143:241-249.
L. corniculatus plants were studied at 2 sites, 200 m apart,
at Oulches, France: one plot of short grass at the mouth of a
limestone quarry abandoned in 1939 and one area cut annually in
early July Whilst 94% of plants in the cut plot were cyanogenic,
the population of L. corniculatus in the limestone plot
was highly polymorphic with 73% of plants not cyanogenic. Adverse
soil conditions led to polymorphism at this site whereas cutting
of the other plot led to homogeneity and selection for vigorous,
fast-growing individuals. The relationship between competitive
ability and cyanogenesis is discussed.