Symbiotic competence of Trifolium subterraneum lines of low oestrogenic isoflavone content

1970 ◽  
Vol 10 (46) ◽  
pp. 555 ◽  
Author(s):  
J Brockwell ◽  
AC Robinson
Keyword(s):  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Rhizobium Trifolii ◽  
Isoflavone Content ◽  
Low Levels ◽  
Better Than

Twenty-nine lines of subterranean clover (Trifolium subterraneum), mostly selected for low levels of oestrogenic isoflavones, were inoculated with seven effective strains of Rhizobium trifolii. They were grown at two different root temperatures and their performances compared with those of the subterraneum clover cultivar, Tallarook. Ten criteria were used to assess symbiotic competence. No line was inferior to Tallarook in all ten criteria, but one line was inferior in nine of the ten, three in seven of the ten and fifteen others were poorer than Tallarook in one to six criteria. Of the ten lines whose symbiotic performances were as good as or better than Tallarook, a number also had low isoflavone levels, but there was no evidence to suggest that symbiotic competence was related to isoflavone content. It is concluded that it will be necessary to exercise caution in the agronomic or breeding use of lines Which are not consistently symbiotically competent.

The in vitro inhibition of Phytophthora clandestina by some rhizobia and the possible role of Rhizobium trifolii in biological control of Phytophthora root rot of subterranean clover

1999 ◽  
Vol 50 (8) ◽  
pp. 1469 ◽  
Author(s):  
S. Simpfendorfer ◽  
T. J. Harden ◽  
G. M. Murray
Keyword(s):  
Biological Control ◽  
Root Rot ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Root Disease ◽  
Rhizobium Trifolii ◽  
Biological Control Agents ◽  
Control Activity ◽  
Phytophthora Root Rot

The interaction between 29 isolates of Rhizobium and the in vitro growth of 3 strains of Phytophthora clandestina was investigated to determine the potential of these bacteria as biological control agents against root rot of subterranean clover (Trifolium subterraneum L.). The biological control activity of Rhizobium on the severity of root disease in seedlings was also investigated under glasshouse conditions. Thirteen of the 29 Rhizobium isolates caused significant reductions in the hyphal growth of the 3 P. clandestina isolates examined. Inoculation of seedlings with Rhizobium trifolii reduced the severity of root disease by 14–58% with corresponding increases in dry matter production of 20–73%. These results indicate that Rhizobium species have potential as biological control agents against the root rot of T. subterraneum seedlings caused by P. clandestina.

Rhizosphere relationships of subterranean clover. I. Interactions between strains of Rhizobium trifolii.

1954 ◽  
Vol 5 (2) ◽  
pp. 247 ◽  
Author(s):  
JR Harris
Keyword(s):  
Nitrogen Fixation ◽  
Host Plant ◽  
Root Zone ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Rhizobium Trifolii ◽  
Rhizobial Strain ◽  
Susceptible Host ◽  
Active Elements ◽  
Indigenous Microflora

A study was made of a number of effective and ineffective strains of Rhizobium trifolii in association with subterranean clover (Trifolium subterraneum L.), variety Bacchus Marsh. Where these were inoculated singly into sterilized soils in pot experiments conducted in the greenhouse, typical effective, ineffective, or intermediate plant reactions were obtained. Where more than one strain was inoculated, competition between strains took place and was reflected in nodule pattern and plant reaction. Some strains consistently failed to produce appreciable nodules in the presence of other rhizobia, some showed modification to varying degrees, and some were unaffected. Such behaviour was found to be closely linked with the ability of the strain to proliferate in the rhizosphere of the host plant, and placement of inoculum was shown to influence plant reaction. The concept of "incursion" as a property of a rhizobial strain is suggested. An incursive strain is one able to migrate from the initial site of inoculation and establish an adequate population in the root zone of the susceptible host despite the presence of active elements of the indigenous microflora and microfauna, including antagonistic and predatory forms. The property of incursion is independent of considerations of efficiency of nitrogen fixation or virulence for the host plant. Strains of rhizobia which are poorly incursive may fail to infect the host upon which they have been inoculated if subject to competition from indigenous rhizobia already established in the soil. The necessity of assessing properties of virulence and incursion as well as efficiency of nitrogen fixation in selecting rhizobia for purposes of commercial inoculation is stressed, and the methods of making such tests are discussed.

Urinary sediments in sheep feeding on oestrogenic clover. I. Preliminary observations on changes in certain urinary constituents

1970 ◽  
Vol 21 (6) ◽  
pp. 933 ◽  
Author(s):  
WJ Parr ◽  
P Steele ◽  
B Gabbedy ◽  
MC Nottle
Keyword(s):  
Direct Relationship ◽  
Daily Intake ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Urinary Calcium ◽  
Direct Result ◽  
Calcium Excretion ◽  
Total Phenols ◽  
Isoflavone Content ◽  
Daily Excretion

In recent years a series of widespread outbreaks of acute urinary obstruction has occurred in spring in Merino wethers. Animals involved have been grazing oestrogenic strains of subterranean clover at a time when isoflavone concentrations can be expected to be high. Studies have been made on one property on the relationships between these outbreaks, the pasture isoflavone content, and the urinary excretion of phenolic and other constituents by wethers. A trial group of animals was grazed on a dominant sward of the highly oestrogenic Trifolium subterraneum cv. Dinninup during winter and spring. Isoflavone concentrations in the clover reached a peak in early August. However, since the pasture became highly clover-dominant in September and early October the maximum daily intake of isoflavones probably occurred during this period, which also coincided with the occurrence of maximum concentration and maximum daily excretion of total phenols and acid-precipitable material (APM) in the urine. It is suggested that the sediments causing clinical obstructions at this time of the year may be a direct result of increased excretion of phenols. APM showed a highly significant direct relationship with total phenols but its excretion increased at a greater rate than did that of phenols. Urinary calcium excretion also increased at the same time.

scholarly journals The Symbiotic Synthesis of Auxin by Legumes and Nodule Bacteria and its Eole in Nodule Development

1960 ◽  
Vol 13 (4) ◽  
pp. 456 ◽  
Author(s):  
NP Kefford ◽  
J Brockwell ◽  
JA Zwar
Keyword(s):  
Acetic Acid ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Nodule Development ◽  
Distilled Water ◽  
Rhizobium Trifolii ◽  
Nodule Bacteria ◽  
Root Medium ◽  
Growth Properties ◽  
Indole 3 Acetic Acid

When subterranean clover (Trifolium subterraneum L.) plants were grown for 3 weeks over distilled water, tryptophan could be detected in the root medium of both sterile cultures and those inoculated with Rhizobium trifolii 3 days earlier. Auxin could be detected only in the inoculated medium. The auxin had the chromatographic and growth properties of indole�3-acetic acid (IAA). Since nodule bacteria produce auxin only in the presence of tryptophan, which is a probable precursor of lAA, it is suggested that the tryptophan exuded by clover roots is converted to lAA by nodule bacteria. Auxin was still produced in the root medium when strains of Rhizobium which do not nodulate subterranean olover roots were used as inooulant, or when nitrate, which delays nodulation, was present in the medium.

Lime and molybdenum in clover development on acid soils

1952 ◽  
Vol 3 (2) ◽  
pp. 95 ◽  
Author(s):  
AJ Anderson ◽  
DV Moye
Keyword(s):  
Acid Soil ◽  
Acid Soils ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Low Levels

In a study of the factors concerned in the effect of lime on subterranean clover (Trifolium subterraneum L.) on an acid soil where nodulation is defective, it has been found that responses equal to those obtained with heavy dressings of lime can be obtained by the application of molybdenum together with only 2 cwt. of lime per acre at seeding. Marked response to molybdenum was obtained only where low levels of lime were used. Where heavier dressings of lime were applied the clover grew normally and did not then require treatment with molybdenum. Where no lime was used nodulation was defective and, during the first two )ears, response to molybdenum did not occur or was very small. Nodulation subsequently improved on the unlimed soil and response to molybdenum progressively increased over the five-year period of the experiments. In the year of sowing best results were obtained where the inoculated seed was drilled with the lime. The evidence suggests that defective nodulation of subterranean clover may be expected on new land where the soil reactions are less than pH 5.0, and that soils of higher pH but with minimum values less than pH 5.5 are also suspect. The importance of treatment with adequate superphosphate in addition to lime and molybdenum in the development of subterranean clover on this acid soil is stressed. The interpretation and significance of the positive and negative lime-molybdenum interactions obtained are discussed.

The effect of anti-fungal antibiotics on the nodulation of Trifolium subterraneum and the estimation of Rhizobium trifolii populations

1968 ◽  
Vol 8 (32) ◽  
pp. 327 ◽  
Author(s):  
AC Robinson
Keyword(s):  
Pure Culture ◽  
Culture Media ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Test Plant ◽  
Rhizobium Trifolii ◽  
Plant Infection ◽  
Micro Organisms ◽  
Anti Fungal ◽  
Test Plants

Three anti-fungal antibiotics (cycloheximide, griseofulvin, and mycostatin) were tested for their effects on inoculated Trifolium subterraneum (subterranean clover). All three influenced the growth and nodulation of the test plant, the effects being least with mycostatin. Mycostatin was further examined for its effect on a plant-infection technique for estimating Rhizobium numbers. The presence in culture media of mycostatin did not impair the accuracy of the plant-infection test for counting rhizobia in a pure culture. Moreover, when the plant-infection technique was used for counting rhizobia in soil, the antibiotic reduced the amount of infection of the test plant by miscellaneous soil micro-organisms, thereby improving nodulation. It is concluded that the incorporation of mycostatin into media (100 p.p.m.) used for growing test plants in plant-infection tests will improve the reliability of the method.

The effect of temperature on the hardseed content of some annual legumes grown on the northern slopes of New South Wales

1990 ◽  
Vol 41 (5) ◽  
pp. 941 ◽  
Author(s):  
GM Lodge ◽  
RD Murison ◽  
EW Heap
Keyword(s):  
Seed Set ◽  
New South ◽  
Trifolium Subterraneum ◽  
Summer Rainfall ◽  
Effect Of Temperature ◽  
South Wales ◽  
Low Levels ◽  
Fluctuating Temperatures ◽  
Over Time ◽  
Better Than

Two laboratory experiments were conducted to assess the effects of constant and fluctuating temperatures on the hardseed content of a range of legume species. In the first experiment the effects of constant (10/10,25/25,40/40�C) and fluctuating temperatures (40/10,40/25�C) on the rate of breakdown of the hardseed of 15 legumes was examined over a 12-month period. The second experiment investigated the hardseed level of seven of these legumes stored at temperatures of 25/25,40/25,60/25�C over 11 months. A method of analysing these data is presented which describes the hardseed profile over time and allows the rates of change to be compared. For seed collected in a summer rainfall environment fluctuating temperatures of 40/10�C significantly reduced the hardseed level of Medicago aculeata Willd. and M. scutellata (L.) Mill, cv. Sava, Trifolium subterraneum ssp. subterraneum Katzn. et Morley cv. Woogenellup and T. subterraneum ssp brachycalycinum Katzn. Et Morley cv. Clare. A 40/25�C regime reduced the hardseededness of M. minima (L.) Bart, M, aculeata, M. truncatula Gaertn. cv. Sephi, T. subterraneum ssp, subterraneum Katzn. et Morley cvv. Nungarin and Woogenellup and cv. Clare. At 60/25�C the hardseed level of all legumes declined over time. Further at 60/25�C hardseed contents declined at a significantly faster rate than for those at 40/25�C. Field observations of the number of seedlings emerging in the summer after seed set followed a similar pattern to that expected from the laboratory studies. From these studies it is proposed that, provided their seed set is adequate, cultivars with comparatively low levels of hardseed may perform better than expected when grown in a summer rainfall environment, particularly when they are either grown in association with native grasses or have a high proportion of buried burrs. Under these conditions temperatures of around 40/25�C could be expected.

Long-term persistence of subterranean clover (Trifolium subterraneum) cultivars in south-western Victoria

1991 ◽  
Vol 31 (5) ◽  
pp. 625 ◽  
Author(s):  
SG Clark ◽  
RM McDonald ◽  
HC Street
Keyword(s):  
Dry Matter ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Seed Banks ◽  
Sheep Grazing ◽  
Level Of Invasion ◽  
Small Seed ◽  
Low Levels ◽  
Western Victoria

The long-term persistence of 6 subterranean clover (Trifolium subterraneum) cultivars was determined by sampling seed from 2 experiments at Hamilton and Beeac in south-western Victoria, 8 or 12 years after sowing. For most of this period the plots were managed as part of the surrounding pasture and were closely grazed by sheep. Herbage yield measurements were made and seed was collected from each plot and grown in a glasshouse, in order to identify the cultivar(s) present. Cultivars used were Yarloop, Trikkala, Larisa and Meteora (spp. yanninicum), and Mount Barker and Woogenellup (spp. subterranean). At both sites, plots sown to Trikkala and Larisa had the greatest seed banks and experienced the lowest level of invasion by other cultivars or ecotypes. Mount Barker and Yarloop appeared to have persisted at low levels; their plots were moderately invaded. Plots sown to the unsuccessful Woogenellup were heavily invaded and contained only a small seed bank of Woogenellup seed. Eight to 12 years after sowing, plots at Hamilton and Beeac that were sown to Larisa produced 3-15 times as much clover dry matter in spring as plots sown to Mount Barker. At Hamilton, the plots sown to Trikkala produced 3 times as much clover in winter as those sown to Mount Barker. This study indicates that Trikkala and Larisa offer clear advantages over the older cultivars, Mount Barker and Woogenellup, for the high rainfall areas of western Victoria, by demonstrating their persistence and long-term productivity when subjected to normal sheep-grazing practice.

Varietal and environmental variations in isoflavone concentrations in subterranean clover (Trifolium subterraneum L.)

1968 ◽  
Vol 19 (1) ◽  
pp. 15 ◽  
Author(s):  
FHW Morley ◽  
CM Francis
Keyword(s):  
Environmental Variables ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Biochanin A ◽  
Components Of Variance ◽  
Isoflavone Concentration ◽  
Environmental Variations ◽  
Breeding Selection ◽  
Low Levels ◽  
Selection For

The concentrations of formononetin, genistein, and biochanin A in leaves of 151 lines belonging to three subspecies of T. subterraneum L. and of 8 lines of T. israeliticum D. Zoh. & Katzn, were measured from plants grown in the field at Perth and Canberra, and in a glasshouse at Perth. The average concentrations did not differ significantly between locations, but did between sampling dates. The components of variance were greater for subspecies, and for varieties within subspecies, than for environmental variables other than error. Interactions were negligible, although some were greater than zero. The component correlations between concentrations of different isoflavones were generally positive where determined by environment, but tended to be negative where determined by genotype, especially that between genistein and biochanin A. Differences among subspecies In level and pattern of isoflavone concentration could be of limited value for taxonomic classification. Differences among varieties within subspecies are sufficient to promise progress in selection for low levels of individual isoflavones by conventional techniques of plant breeding. Selection for low levels of total isoflavones would be hindered, but not prevented, by the negative genotypic correlations between concentrations of genistein and biochanin A.

Plant productivity and persistence in mixed pastures containing lucerne at a range of densities with subterranean clover or phalaris

1980 ◽  
Vol 20 (103) ◽  
pp. 189 ◽  
Author(s):  
EC Wolfe ◽  
OR Southwood
Keyword(s):  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Plant Productivity ◽  
The Other ◽  
Total Production ◽  
Dominant Component ◽  
Annual Productivity ◽  
Companion Plant ◽  
Selection Of ◽  
Better Than

Lucerne (Medicago sativa cv. Hunter River) was sown at three densities (rows spaced 17.5, 35 and 52.5 cm apart) in factorial combination with each of three cultivars of subterranean clover (Trifolium subterraneum cw. Geraldton, Seaton Park and Woogenellup) and two of phalaris (a summer-dormant selection of P. aquatics, and a P. aquatica-P. arundinacea hybrid). All three clover cultivars were included in the lucerne-phalaris swards. After the establishment year, plant productivity and persistence in these mixtures were assessed under rotational grazing over the next three years. Lucerne density had little effect on the total seasonal or annual productivity of the swards. Lucerne grew and survived best with Geraldton clover and worst with the phalaris hybrid; total pasture yields reflected these differences in summer (two occasions) or autumn (one occasion) when lucerne was the dominant component. In winter, when lucerne grew slowly, the cultivar of clover was an important factor influencing total production. A mixed sward of lucerne and Seaton Park clover grew as well as or better than the other mixtures in winter, and occasionally in summer-autumn it was more productive than lucerne-phalaris, Seaton Park persisted with lucerne better than did any other companion plant.

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