Effects of cultivar and growing degree day accumulations on forage partitioning and nutritive value of common vetch (Vicia sativa L.) on the Tibetan plateau.

BACKGROUND: The use of common vetch in grassland-livestock systems has expanded greatly within recent years, partly because of its value as a high-quality forage crop but also to improve the soil nitrogen availability. In-field estimation of forage yield potential and nutritional characteristics is required for providing management decision to farmers on how to optimize the management and use of common vetch forages. The aim of this work was to study changes in forage partitioning and nutritive value responses of a late-maturing and an early maturing cultivar of common vetch in a two-year study on the Tibetan Plateau. RESULTS: This study provided evidence for differential patterns of forage accumulation for common vetch with contrasting maturity over 2 years. The late-maturing cultivar exhibited greater forage yield and a lower proportion of pods, compared to the early maturing cultivar. There was a tendency towards lower forage nutritive value with the late-maturing cultivar. Regressions of nutritive value parameters of common vetch forages on growing degree days were explained by the cubic (P < 0.001) models, all with high coefficients of determination (R2 ≥ 0.792). CONCLUSION: This study shows that the late-maturing cultivar harvested at end of the pod-filling stage produces high forage yield, increasing the availability of high-quality forage for ruminants, thereby improving the self-sufficiency of farmers, in terms of forage yield and high-concentration protein. For early maturing cultivars, it may be better to harvest at the early flowering stage for better nutritive value and in part to enable a subsequent double crop of oat. © 2020 Society of Chemical Industry.

Breaking continuous potato cropping with legumes improves soil microbial communities, enzyme activities and tuber yield.

This study was conducted to explore the changes in soil microbial populations, enzyme activity, and tuber yield under the rotation sequences of Potato-Common vetch (P-C), Potato-Black medic (P-B) and Potato-Longdong alfalfa (P-L) in a semi-arid area of China. The study also determined the effects of continuous potato cropping (without legumes) on the above mentioned soil properties and yield. The number of bacteria increased significantly (p < 0.05) under P-B rotation by 78%, 85% and 83% in the 2, 4 and 7-year continuous cropping soils, respectively compared to P-C rotation. The highest fungi/bacteria ratio was found in P-C (0.218), followed by P-L (0.184) and then P-B (0.137) rotation over the different cropping years. In the continuous potato cropping soils, the greatest fungi/bacteria ratio was recorded in the 4-year (0.4067) and 7-year (0.4238) cropping soils and these were significantly higher than 1-year (0.3041), 2-year (0.2545) and 3-year (0.3030) cropping soils. Generally, actinomycetes numbers followed the trend P-L>P-C>P-B. The P-L rotation increased aerobic azotobacters in 2-year (by 26% and 18%) and 4-year (40% and 21%) continuous cropping soils compared to P-C and P-B rotation, respectively. Generally, the highest urease and alkaline phosphate activity, respectively, were observed in P-C (55.77 mg g-1) and (27.71 mg g-1), followed by P-B (50.72 mg mg-1) and (25.64 mg g-1) and then P-L (41.61 mg g-1) and (23.26 mg g-1) rotation. Soil urease, alkaline phosphatase and hydrogen peroxidase activities decreased with increasing years of continuous potato cropping. On average, the P-B rotation significantly increased (p <0.05) tuber yield by 19% and 18%, compared to P-C and P-L rotation respectively. P-L rotation also increased potato tuber yield compared to P-C, but the effect was lesser relative to P-B rotation. These results suggest that adopting potato-legume rotation system has the potential to improve soil biology environment, alleviate continuous cropping obstacle and increase potato tuber yield in semi-arid region.

Selection and characterization of coal mine autochthonous rhizobia for the inoculation of herbaceous legumes.

Coal open pit mining in the South of Santa Catarina state (Brazil) was inappropriately developed, affecting approximately 6.700 ha. Re-vegetation is an alternative for the recovery of these areas. Furthermore, the use of herbaceous legumes inoculated with nitrogen fixing bacteria is motivated due to the difficulty implementing a vegetation cover in these areas, mainly due to low nutrient availability. Therefore, the aim of this work was to evaluate, among 16 autochthonous rhizobia isolated from the coal mining areas, those with the greatest potential to increase growth of the herbaceous legumes Vicia sativa and Calopogonium mucunoides. Tests were conducted in greenhouse containing 17 inoculation treatments (16 autochthonous rhizobia + Brazilian recommended strain for each plant species), plus two treatments without inoculation (with and without mineral nitrogen). After 60 days, nodulation, growth, N uptake, and symbiotic efficiency were evaluated. Isolates characterization was assessed by the production of indole acetic acid, ACC deaminase, siderophores, and inorganic phosphate solubilization. The classification of the isolates was performed by 16 S rDNA gene sequencing. Only isolates UFSC-M4 and UFSC-M8 were able to nodulate C. mucunoides. Among rhizobia capable of nodulating V. sativa, only UFSC-M8 was considered efficient. It was found the presence of more than one growth-promoting attributes in the same organism, and isolate UFSC-M8 presented all of them. Isolates were classified as belonging to Rhizobium, Burkholderia and Curtobacterium. The results suggest the inoculation of Vicia sativa with strain UFSC-M8, classified as Rhizobium sp., as a promising alternative for the revegetation of coal mining degraded areas.

Cd-induced oxidative stress and lignification in the roots of two Vicia sativa L. varieties with different Cd tolerances.

We examined the effects of Cd on growth, lipid peroxidation, reactive oxygen species (ROS) accumulation, antioxidant enzymatic activity, and lignin content in the roots of two varieties of Vicia sativa. Treatment with Cd decreased plant growth and increased ROS and lipid peroxidation levels to a greater extent in the Cd-sensitive variety ZM than in the Cd-tolerant variety L3. Most hydrogen peroxide (H2O2) and superoxide anion (O2(•-)) were accumulated in the cell walls and extracellular spaces in response to Cd treatments. Chemical assays and experiments using inhibitors showed that larger increases in H2O2 and O2(•-) production in ZM than in L3 were probably attributed to elevated Cd-induced nicotinamide adenine dinucleotide-peroxidase (NADH-POD) activity. Cd treatment increased the accumulation of lignin and the guaiacol peroxidase (GPOD) activities in the apoplast more significantly in ZM root than in L3. Howerver, root laccase activity was higher in L3 than in ZM. Thus Cd toxicity induced significant lignification in the roots of V. sativa, and increases in H2O2 accumulation and apoplastic GPOD activity were likely responsible for this effect.

Accumulation of nickel ions in seedlings of Vicia sativa L. and manifestations of oxidative stress.

The accumulation of nickel ions in the roots and shoots of vetch seedlings (Vicia sativa L.) at increasing concentrations of nickel chloride in the medium was studied. It was shown that the accumulation of nickel in the shoots was increased when the concentration of nickel chloride in the medium was more than 50 µM. The bioconcentration factor and sustainability index for vetch seedlings were calculated under the experimental conditions. The obtained results were similar to parameters for other plants, grown on a nutrient medium or soil substrate. First, the obtained results allowed estimate the limits of nickel chloride concentrations for four of five zones, which correspond to the theoretical concept of dose-response curves in the studies on the influence of physiologically essential heavy metals on plants (Prasad 2010). Some parameters of oxidative stress caused by the presence of nickel chloride in the medium were shown. It seems that at low nickel concentrations in the medium in vetch seedlings the increase of several biochemical parameters (catalase activity and proline) caused by the high amylase activity in seeds.

Response to copper bromide exposure in Vicia sativa L. seeds: analysis of genotoxicity, nucleolar activity and mineral profile.

Copper bromide (CuBr2) effects on seed germination and plantlet development of Vicia sativa L. are evaluated through mitotic index, chromosome aberrations, nucleolar activity and mineral profile. CuBr2 induces a significant presence of micronuclei, sticky and c-metaphases, anaphase bridges and chromosome breaks. Increased number of nucleoli and scattering of AgNOR proteins from the nucleolus in the nuclear surface at CuBr2 1mM and in the cytoplasm at CuBr2 5mM, goes along with the decrease of root growth. In V. sativa embryo the content of many macro and micronutrients increases up to copper 1mM in agreement with reserve mobilization while at CuBr2 5mM some elements are present in lower amount. We hypothesize that inhibitory effects observed at 5mM are due either to a nutrient shortage or to a direct influence of copper on root cell division, evidenced by low mitotic index, high occurrence of chromosome aberrations and loss of material from the nucleolus.

Metabolic responses in root nodules of Phaseolus vulgaris and Vicia sativa exposed to the imazamox herbicide.

Alterations on growth, amino acids metabolism and some antioxidant enzyme activities as result of imazamox treatment were examined in determinate and indeterminate nodules, formed by Phaseolus vulgaris and Vicia sativa, respectively. Young seedlings of both legumes were inoculated with their respective microsymbionts and grown under controlled conditions. At vegetative growth, plants were treated with imazamox (250µM) in the nutrient solution and harvested 7days after. Imazamox was mainly accumulated in V. sativa where concentrations were more than six fold higher than those detected in P. vulgaris. Nodule dry weight and total nitrogen content were reduced by the herbicide treatment: the highest decrease of nodule biomass (50%) and nitrogen content (40%) were registered in V. sativa and P. vulgaris, respectively. The concentration of branched-chain amino acids (BCAA) did not change in neither determinate nor indeterminate nodules even though the acetohydroxyacid synthase activity decreased in root and nodules of both symbioses with the herbicide application. Based on this last result and taking into account that total free amino acids increased in roots but not in nodules of common vetch, a possible BCAA translocation from root to nodule could occur. Our results suggest that the maintenance of BCAA balance in nodule become a priority for the plant in such conditions. The involvement of activities glutathione-S-transferase, guaiacol peroxidase and superoxide dismutase in the response of the symbioses to imazamox are also discussed.

Physiological and biochemical responses of common vetch to the imazamox accumulation.

Common vetch (Vicia sativa L.) is a forage and grain legume, widely distributed throughout the world. Alterations induced by the herbicide imazamox on plant growth, acetohydroxyacid synthase activity, total free amino acids, as well as concentrations of valine, leucine, isoleucine and imazamox in young and mature leaves were investigated at 2 and 7 days after the herbicide application. Plant growth decreased significantly after 7 days of imazamox treatment. The herbicide was detected in both young and mature leaves inducing an inhibition of acetohydroxyacid synthase activity in the former and consequently decreasing valine and leucine contents in this organ. At the same time, the treatment caused an increase of total free amino acids in young leaves, presumably as result of proteolysis stimulation in such conditions. Given that these effects were not observed in mature leaves, we suggest a different sensitivity of the acetohydroxyacid synthase activity to imazamox depending on leaf age. Common vetch seems not to degrade imazamox since the herbicide was accumulated in shoot with increasing treatment time. To our knowledge, no physiological and biochemical studies of common vetch responses to imazamox have been previously reported.

Comparative transcriptional profiling provides insights into the evolution and development of the zygomorphic flower of Vicia sativa (Papilionoideae).

BACKGROUND: Vicia sativa (the common vetch) possesses a predominant zygomorphic flower and belongs to the subfamily Papilionoideae, which is related to Arabidopsis thaliana in the eurosid II clade of the core eudicots. Each vetch flower consists of 21 concentrically arranged organs: the outermost five sepals, then five petals and ten stamens, and a single carpel in the center. METHODOLOGY/PRINCIPAL FINDINGS: We explored the floral transcriptome to examine a genome-scale genetic model of the zygomorphic flower of vetch. mRNA was obtained from an equal mixture of six floral organs, leaves and roots. De novo assembly of the vetch transcriptome using Illumina paired-end technology produced 71,553 unigenes with an average length of 511 bp. We then compared the expression changes in the 71,553 unigenes in the eight independent organs through RNA-Seq Quantification analysis. We predominantly analyzed gene expression patterns specific to each floral organ and combinations of floral organs that corresponded to the traditional ABC model domains. Comparative analyses were performed in the floral transcriptomes of vetch and Arabidopsis, and genomes of vetch and Medicago truncatula. CONCLUSIONS/SIGNIFICANCE: Our comparative analysis of vetch and Arabidopsis showed that the vetch flowers conform to a strict ABC model. We analyzed the evolution and expression of the TCP gene family in vetch at a whole-genome level, and several unigenes specific to three different vetch petals, which might offer some clues toward elucidating the molecular mechanisms underlying floral zygomorphy. Our results provide the first insights into the genome-scale molecular regulatory network that controls the evolution and development of the zygomorphic flower in Papilionoideae.

Phytoremediation of phenol using Vicia sativa L. plants and its antioxidative response.

Common vetch (Vicia sativa L.) is a legume species with an extensive agricultural use. However, the phytoremediation potentiality of this species has not been sufficiently explored because little is known about its resistance to inorganic and organic pollutants. In the present work, phenol tolerance of common vetch was assayed at different stages of growth. Germination index and germination rate decreased only at high phenol concentrations (250 and 500 mg L(-1)), whereas 30-day-old plants were able to tolerate this pollutant, with high removal efficiencies. The activities of antioxidative enzymes, such as peroxidase (POD) and ascorbate peroxidase, increased significantly with the highest phenol concentration, whereas superoxide dismutase activity, malondialdehyde, and H(2)O(2) levels remained unaltered. Besides, an increase in two basic isoforms of POD was observed in plants treated with phenol. The results suggested that common vetch has an efficient protection mechanism against phenol-induced oxidative damage. Moreover, it could tolerate and remove high phenol concentrations, avoiding serious phytotoxic effects. Thus, V. sativa could be considered an interesting tool in the field of phytoremediation.

Environmental assay on the effect of poultry manure application on soil organisms in agroecosystems.

This paper reports the effects produced on the organisms of the soil (plants, invertebrates and microorganisms), after the application of two types of poultry manure (sawdust and straw bed) on an agricultural land. The test was made using a terrestrial microcosm, Multi-Species Soil System (MS3) developed in INIA. There was no difference in the germination for any of the three species of plants considered in the study. The biomass was increased in the wheat (Triticum aestivum) coming from ground treated with both kinds of poultry manure. Oilseed rape (Brasica rapa) was not affected and regarding vetch (Vicia sativa) only straw poultry manure showed significant difference. For length only Vicia sativa was affected showing a reduction when straw was exposed to poultry manure. When the effect on invertebrates was studied, we observed a reduction in the number of worms during the test, especially from the ground control (13.7%), higher than in the ground with sawdust poultry manure (6.7%), whereas in the ground with straw poultry manure, there was no reduction. The biomass was affected and at the end of the test it was observed that while the reduction of worms in the ground control was about 48%, the number of those that were in the ground with sawdust poultry manure or straw poultry manure decreased by 41% and 22% respectively. Finally, the effects on microorganisms showed that the enzymatic activities: dehydrogenase (DH) and phosphatase and basal respiration rate increased at the beginning of the test, and the differences were statistically significant compared with the values of the control group. During the test, all these parameters decreased (except DH activities) but they were always higher than in the ground control. This is why it is possible to deduce that the contribution of poultry manure caused an improvement in the conditions of fertilization and also for the soil.

The influence of plant polyphenols on lipolysis and biohydrogenation in dried forages at different phenological stages: in vitro study.

BACKGROUND: It is known that forage legumes show a higher transfer efficiency of polyunsaturated fatty acids (PUFA) to ruminant dairy products in comparison with grasses. Legumes are usually characterised by moderate levels of plant secondary metabolites, which can have an effect on lipolysis and biohydrogenation in the rumen. An in vitro study was carried out to compare two species with different plant phenol compositions, Vicia sativa (VS, common vetch, cv. Jose) and Trifolium incarnatum (TI, crimson clover, cv. Viterbo) cut at the vegetative (Veg) and reproductive (Rep) stages, on lipolysis and PUFA biohydrogenation in the rumen. RESULTS: The study showed that forage species and phenological stage affected the levels of bound phenols (BP) and tannic polyphenols (TP). VS was characterised by a higher level of TP than TI at both Veg and Rep stages, whereas BP levels were low in both forages. BP and TP had a negative effect on lipolysis and biohydrogenation, but TP showed a greater negative correlation than BP for both forages. CONCLUSION: These results showed that lipolysis and biohydrogenation of PUFA could be affected by plant phenols, particularly TP.

Accumulation of lipochitin oligosaccharides and NodD-activating compounds in an efficient plant--Rhizobium nodulation assay.

During legume plant--Rhizobium spp. interactions, leading to the formation of nitrogen-fixing root nodules, the two major determinants of host plant-specificity are plant-produced nod gene inducers (NodD protein activating compounds) and bacterial lipochitin oligosaccharides (LCOs or Nod factors). In a time course, we describe the accumulation of LCOs in an efficient nodulation assay with Vicia sativa subsp. nigra and Rhizobium leguminosarum, in connection with the presence of NodD-activating compounds in the exudate of V. sativa roots. Relatively small amounts of both LCOs and NodD-activating compounds were found to be required for initiation of nodulation during the first days after inoculation. A strong increase in the amount of NodRlv-V[18:4,Ac] LCOs preceded root infection and nodule primordium formation. In contrast to the situation with non-nodulating rhizobia and nonmitogenic LCOs, the amount of NodD-activating compounds in the culture medium remained small after addition of nodulating rhizobia or mitogenic LCOs. Furthermore, addition of nodulating rhizobia or mitogenic LCOs resulted in nearly complete inhibition of root hair formation and elongation, whereas nonmitogenic LCOs stimulated root hair growth. Retention of NodD-activating compounds in the root may inhibit root hair growth.

The effect of diesel fuel on common vetch (Vicia sativa L.) plants.

When petroleum hydrocarbons contaminate soil, the carbon:nitrogen (C:N) ratio of the soil is altered. The added carbon stimulates microbial numbers but causes an imbalance in the C:N ratio which may result in immobilization of soil nitrogen by the microbial biomass, leaving none available for plant growth. As members of Leguminosae fix atmospheric nitrogen to produce their own nitrogen for growth, they may prove more successful at growing on petroleum hydrocarbon contaminated sites. During a wider study on phytoremediation of diesel fuel contaminated soil, particular attention was given to the performance of legumes versus other plant species. During harvesting of pot experiments containing leguminous plants, a recurring difference in the number and formation of root nodules present on control and contaminated Common vetch (Vicia sativa L.) plants was observed. The total number of nodules per plant was significant reduced in contaminated plants compared to control plants but nodules on contaminated plants were more developed than corresponding nodules on control plants. Plant performance of Common vetch and Westerwold's ryegrass (Lolium multiflorum L.) was compared to illustrate any difference between the ability of legumes and grasses to grow on diesel fuel contaminated soil. Common vetch was less affected by diesel fuel and performed better in low levels of diesel fuel contaminated soil than Westerwold's ryegrass. The total amount of diesel fuel remaining after 4 months in Common vetch planted soil was slightly less than in Westerwold's ryegrass planted soil.