Manganese toxicity in Trifolium balansae, T. resupinatum, T. subterraneum, Medicago murex, M. polymorpha, M. sativa, Lotus pedunculatus, and Ornithopus compressus: relative tolerance and critical toxicity concentrations

1995 ◽  
Vol 35 (3) ◽  
pp. 367 ◽  
Author(s):  
DGDe Marco ◽  
CB Li ◽  
PJ Randall ◽  
Marco DG De

This paper describes the tolerance to high concentrations of manganese (Mn) of pasture legumes that are suitable for the >500 mm rainfall zone in southern Australia. The legumes are lucerne (Medicago sativa), burr medic (M. polymorpha), murex medic (M. murex), balansa clover (Trifolium balansae), Persian clover (T. resupinatum), subterranean clover (T: subterraneum), greater lotus (Lotus pedunculatus), and seradella (Ornithopus compressus). Wheat (Triticum aestivum) cv. Egret and subterranean clover cvv. Mt Barker and Karridale were included to place the tolerance of the remaining species in the context of other studies.Symptoms of toxicity differed between species. Species ranking (in descending order) for Mn tolerance, and external threshold Mn concentrations (mmol/L), were subterranean clover (1.0), wheat (0.71), balansa clover (0.54), greater lotus (0.51), serradella (0.50), Persian clover (0.25), murex medic (0.24), burr medic (0.20), and lucerne (0.19). Critical toxicity concentrations derived from the relationships of yields to Mn concentrations in whole shoots for each species were as follows (mg Mn/kg DW): subterranean clover (2010), balansa clover (1330), serradella (1080), greater lotus (760), wheat (570), burr medic (440), murex medic (430), Persian clover (360), lucerne (190).

1992 ◽  
Vol 32 (3) ◽  
pp. 331 ◽  
Author(s):  
GB Taylor ◽  
MA Ewing

Annual rates of seed softening were determined from 4 lines of burr medic (Medicago polymorpha), 1 barrel medic (M. truncatula), and 1 subterranean clover (Trifolium subterraneum) grown at Merredin in the 1 year. Measurements were also made on one of the lines of burr medic grown in 2 other environments, Gnowangerup and Eneabba, in the same year. Burrs were placed on the soil surface at Merredin and the numbers of residual hard seeds determined each year for up to 5 years in this one environment. Patterns of softening of seeds from the same seed populations were also determined in a laboratory oven with a diurnal temperature fluctuation of 60/15�C. In the field, the softening rates of the 5 medics grown at Merredin were similar, averaging 21% of the original seeds each year for the first 4 years. Seeds of the burr medic grown in a more favourable environment at Eneabba were much slower to soften (averaging 14%); hence, hardseededness in these medics was influenced more by the growing environment than by genotype. More than half of the seeds of subterranean clover softened in the field over the first summer, with declining annual proportions thereafter. There were clear differences between the clover and medics in both pattern and rate of seed softening. The lower seed-softening rate of medics than of subterranean clover was more favourable for ley systems involving frequent cropping, especially in low rainfall areas. Treatment of seeds at 60/15�C simulated field softening for subterranean clover well but produced misleading results for the medics.


1990 ◽  
Vol 30 (4) ◽  
pp. 507 ◽  
Author(s):  
BH Paynter

The phosphate (P) requirements of burr medic (Medicago polymorpha) on marginally acidic, medium-textured soils and yellow serradella (Ornithopus compressus) on acidic, light-textured soils in the low rainfall (<400 mm) wheatbelt of Western Australia are not known. The hypothesis that yellow serradella, subterranean clover (Trifolium suhrerraneum) and burr medic have the same external requirement for applied P was tested in a glasshouse trial on 2 P-deficient soils. Species were compared on an equal total seed weight and similar maturity length basis. It was found that yellow serradella required less soil applied P to achieve 90% maximum shoot production or total plant (shoots + roots) growth and had a greater curvature co-efficient from fitted Mitscherlich functions than either subterranean clover or burr medic. Burr medic was the most responsive to applied P and had the largest external requirement for applied P. These differences in external P requirements were related to differences in ability of the 3 legumes to absorb P and to transport it to their shoots and were not due to differences in internal efficiency of the shoots. Yellow serradella was able to take up more P (total plant P content) per g roots than subterranean clover, and subterranean clover more than burr medic. The same relationship applied to the translocation of absorbed P from roots to shoots.


1992 ◽  
Vol 43 (5) ◽  
pp. 1229 ◽  
Author(s):  
RAC Jones

Trials were done in 1988-90 to examine the effects of infection with three non persistently aphid-transmitted viruses on the productivity of manually inoculated spaced plants of annual pasture legumes growing in plots. Alfalfa mosaic virus (AMV) decreased herbage and root production (dry weights) of three subterranean clover (Trifolium subterraneum L.) cultivars by 20-49%. Cucumber mosaic virus (CMV) decreased herbage and root production of a murex medic (Medicago murex Wild.) cultivar by 78-90% and of two burr medic (M. polymorpha L.) cultivars by 56-82%. A mild isolate of bean yellow mosaic virus (BYMV) decreased herbage and root production of a subterranean clover cultivar by 31-40%, but with a severe isolate the corresponding losses were 60-63010 in the same cultivar and 79-80% in another. The severe BYMV isolate caused losses in herbage and root production of 38-61% in two burr medic cultivars. Seed yield losses recorded due to infection of subterranean clover were 71% with AMV and 58-76% with BYMV (severe isolate); both viruses decreased seed size as well as seed yield. CMV decreased seed yield by 94% in a burr medic cultivar; it also decreased seed size.


1985 ◽  
Vol 25 (4) ◽  
pp. 850 ◽  
Author(s):  
MJ Barbetti

The effects of inoculum level, and temperature and humidity regimes on the development of Cercospora blackstem disease (caused by Cercospora zebrina) in subterranean clover (Trifolium subterraneum) were investigated. Mycelial fragments were an effective and reliable inoculum. The incidence, severity, and the rate of disease development increased with increasing period of high humidity after inoculation and with increasing concentrations of inoculum. Disease was greatest at 18/13� (12/12 h, day/ night), followed by 21/16�C, and then l5/10�C While all cultivars of T. subterraneum sprayed with hyphal fragments of C. zebrina became infected, Trikkala and Larisa showed some resistance. Of the alternative pasture legumes, lucerne (Medicago sativa), medic (M. littoralis, M. truncatula), drooping-flowered clover (T. cernuum), strawberry clover (T. fragiferum), rose clover (T. hirtum) and white clover (T. repens) were all susceptible; only serradella (Ornithopus compressus) was resistant.


1990 ◽  
Vol 30 (1) ◽  
pp. 55 ◽  
Author(s):  
J Evans ◽  
B Dear ◽  
GE O'Connor

Balansa, persian and subterranean clover and barrel and murex medic were grown in acidic sandy loam in pots in a glasshouse. Four lime treatments (0, 1, 2, 3.5 t/ha) resulted in pH levels of 4.2, 4.7, 5.1 and 6.0 (1:5 CaCl2). After addition of plant nutrients, total exchangeable cations in the nil lime treatment averaged 2.197 cmol(+)/kg, increasing to 4.738 cmol(+)/kg at pH 6.0. With increasing pH, aluminium saturation of the soil exchange was 38, 14, 4 and 3%. The effect of soil acidity on dry matter production was compared between legumes by determining relative yield (yield/maximum yield) responses over the pH range. Subterranean clover was the most tolerant legume, followed by murex medic and balansa clover (similar), persian clover and then barrel medic. All legumes except barrel medic produced at least 90% of maximum yield at pH 4.7; only subterranean clover produced more than 90% of maximum yield at pH 4.2. Establishment of nodules was more sensitive to acidity than indicated by relative yields of dry matter, especially in murex medic and persian clover. Average nodule weight usually increased at lower pH. The dry matter yields of murex medic and persian clover at lower pH were probably reliant on compensatory increases in nodule volume as nodule number declined with increasing acidity.


1988 ◽  
Vol 28 (6) ◽  
pp. 765 ◽  
Author(s):  
MDA Bolland ◽  
MJ Baker

Seed of 2 cultivars of wheat (Triticum aestivum) and 1 burr medic (Medicago polymorpha) with increasing phosphorus (P) concentrations (wheat 1.4-3.7 g P/kg dry matter, medic 3.3-7.9 g P/kg dry matter) were collected from field experiments with variable levels of applied superphosphate (wheat 0- 577 kg P/ha, medic 0-364 kg P/ha) in south-western Australia. These seeds were used in further experiments to examine the effect of seed P concentration on the subsequent dry matter (DM) production of seedlings and plants in 3 glasshouse pot experiments and 1 field experiment. Seed of the same size (wheat, 35 mg/seed; medic, 3.6 mg/seed) but with increasing P concentration produced substantially higher DM yields in the absence or presence of freshly applied superphosphate P up to 28-35 days after sowing in the pot experiments and 67 days after sowing in the field experiment.


1991 ◽  
Vol 133 (2) ◽  
pp. 297-299 ◽  
Author(s):  
J. G. Paull ◽  
A. J. Rathjen ◽  
B. Cartwright

2013 ◽  
Vol 64 (4) ◽  
pp. 409 ◽  
Author(s):  
Bidhyut Kumar Banik ◽  
Zoey Durmic ◽  
William Erskine ◽  
Phillip Nichols ◽  
Kioumars Ghamkhar ◽  
...  

Biserrula (Biserrula pelecinus L.) is an important annual pasture legume for the wheatbelt of southern Australia and has been found to have lower levels of methane output than other pasture legumes when fermented by rumen microbes. Thirty accessions of the biserrula core germplasm collection were grown in the glasshouse to examine intra-specific variability in in vitro rumen fermentation, including methane output. One biserrula cultivar (Casbah) was also grown at two field locations to confirm that low methanogenic potential was present in field-grown samples. All of the biserrula accessions had significantly reduced methane [range 0.5–8.4 mL/g dry matter (DM)] output compared with subterranean clover (28.4 mL/g DM) and red clover (36.1 mL/g DM). There was also significant variation in fermentability profiles (except for volatile fatty acids) among accessions of the core collection. Methanogenic potential exhibited 86% broad-sense heritability within the biserrula core collection. The anti-methanogenic and gas-suppressing effect of biserrula was also confirmed in samples grown in the field. In conclusion, biserrula showed variability in in vitro fermentation traits including reduced methane production compared with controls. This bioactivity of biserrula also persists in the field, indicating scope for further selection of biserrula as an elite methane-mitigating pasture.


2020 ◽  
Vol 27 ◽  
pp. 293-298
Author(s):  
V. F. Valyuk ◽  
R. A. Yakymchuk ◽  
L. Yu. Sobolenko ◽  
S. I. Sorokina

Aim. To study the frequency and spectrum of cytogenetic disorders in Triticum aestivum L. with prolonged action on soil xenobiotic seeds of toxic waste storage areas and to explore the level of their mutagenic activity in comparison with the action of NMS’s moderate and high concentrations. Methods. Cytogenetic disorders induced by soil’s chemical contamination of toxic waste landfill of Dombrovsky Quarry dump (Kalush city) and influence of NMS’s moderate and high concentrations were determined in the cells of the meristem root using the ana-thelophase method. Results. Soil’s chemical contamination of the studied objects exhibits high mutagenic activity, which exceeds the control level by 1.8–3.8 times and does not yield to the mutagenic activity of NMS’s moderate concentrations. The high frequency of chromosomal aberrations at the low concentration of hexachlorobenzene in the soil of the Dombrovsky Quarry dumps is a consequence of its complex interaction with natural mineral compounds of the mountain chemical raw materials. Conclusions. The increasing of the spectrum of cytogenetic disorders induced by chemical soil contamination the proportion of bridges and the chromosomal rings testify radiomimetic properties of the mutagenic factors. The increasing of the number of cells with multiple aberrations indicates a high genotoxicity of hexachlorobenzene and the risk of serious genetic consequences in the case of falling it’s into the environment. Keywords: Triticum aestivum L., toxic waste, mitosis disorders, chromosomal aberrations, mutagenic activity.


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