Uptake studies of environmentally hazardous (51)Cr in Mung beans

Attempt has been made to study the accumulation behaviour of a common plant, Mung bean (Vigna radiata) towards Cr(III) and Cr(VI) to have an insight on the migration and bio-magnification of Cr. For this purpose healthy germinated Mung bean seeds were sown in the sand in the presence of Hoagland's nutrient solution containing measured amount of K(2)(51)Cr(2)O(7) and (51)Cr(NO(3))(3).9H(2)O. Growth rate was also studied in the presence and absence of phosphate salts in the medium. It has been found that the transfer of chromium from soil to plant is significantly low (maximum 5% for both Cr(III) and Cr(VI)). Maximum accumulation of Cr occurs in the root with respect to the total chromium accumulation by the plant. Other parts of the Mung bean plant, e.g. cotyledons, shoot and leaves, show negligible accumulation. Therefore, the chance of direct intake of Cr through food as well as through the grazing animals to human body is less.     

COLONIZATION OF VIGNA RADIATA ROOTS BY CHROMIUM RESISTANT BACTERIAL STRAINS OF OCHROBACTRUM INTERMEDIUM, BACILLUS CEREUS AND BREVIBA CTERIUM SP.

The rhizosphere is the constricted zone of soil surrounding theroot that is under the immediate influence of root system.This zoneis rich in nutrients compared with bulk soil,due to the accumula-tion of various organic compounds released from roots by exu…     

Comparative growth response of two varieties of <Emphasis Type="Italic">Vigna radiata</Emphasis> L. (var. PDM 54 and var. NM 1) grown on different tannery sludge applications: effects of treated wastewater and ground water used for irrigation

This study evaluates the possibility of using contaminated soil by treated tannery wastewater and the use of tannery sludge in agriculture. The plants of Vigna radiata var. PDM 54 grown on contaminated soil and irrigated with ground water have not shown the translocation of toxic metal (Cr) in the upper part. The biomass of the plant increased when irrigated with treated tannery wastewater compared to ground water, whereas no significant change was observed in chlorophyll and protein contents. In both the varieties (var. PDM 54 and var. NM 1) of V. radiata grown on tannery sludge amendments, the growth parameters exhibited a pronounced positive growth response up to 35% tannery sludge amendments compared with the plants grown on garden soil. Despite the Cr accumulation at lower amendments, no toxicity symptoms were observed in both the varieties of the plants. Higher amendments affected various growth parameters, NR activity, and carbohydrate content of the plants. The results suggest that the plants of V. radiata (var. PDM 54) may be grown on contaminated soil or lower sludge amendments and irrigated with ground water. No translocation of toxic metal Cr was found in the seeds of the plants grown in up to 25% tannery sludge. However, periodical monitoring is required before the consumption of seeds. Overall, the results showed that plant growth patterns were influenced to some extent by the level of soil contamination and the water used for irrigation.     

Studies on the influence of mycorrhiza on the growth and physiology of Vigna unguiculata and Abelmoschus esculentus

Diverse forms of microorganisms present in the soil and near the roots of plants, which play a vital role in numerous physiological processes, have attracted the attention of scientists. The dynamic microbial associations may be saprophytic, pathogenic, or symbiotic. The most widespread symbiosis of plants is the mycorrhizal association between root-inhabiting fungi and the feeder roots of plants. The present study was conducted to study the effects of arbuscular mycorrhizal fungi on mineral nutrition of Vigna unguiculata and Abelmoschus esculentus. The experiment comprised of uninoculated seedlings and seedlings inoculated with Glomus mosseae. The chlorophyll a, chlorophyll b, total chlorophyll, carotenoid, protein, nitrate, nitrogen, and phosphorus content showed an increase in vesicular arbuscular mycorrhiza fungus-treated seedlings compared to non-mycorrhizal plants. The total soluble sugars and soluble starch content in leaves of all selected plant species in the present study showed a decrease in mycorrhizal seedlings compared to non-mycorrhizal seedlings.     

Growth and metal accumulation response of <Emphasis Type="Italic">Vigna radiata</Emphasis> L. var PDM 54 (mung bean) grown on fly ash-amended soil: effect on dietary intake

Plants of Vigna radiata L. var. PDM 54 (mung bean) were grown in soil amended with different amounts (10 and 25%) of fly ash (FA). Although total metal content increased with increasing FA amendment, DTPA-extractable metals were higher for 10% FA. Accumulation of metals by the plants increased with increasing FA amendment and was greater in shoots than in roots (except for Mn and Cu) and seeds (except Mn). The total daily intake (TDI) of all the tested metals in seeds was within the recommended dietary allowance (RDA)/provisional tolerable daily intake (PTDI) for adults, except for Cd, which was higher than recommended values. Principal-components analysis (PCA) based on studies of physicochemical properties, DTPA-extractable metals, and metal accumulation in the different parts of V. radiata showed that physicochemical properties such as cation-exchange capacity, organic carbon, and organic matter had significant positive effects on accumulation of Cd, Co, Ni, and Pb by the plant, whereas EC had a significant negative effect. Although addition of fly ash (10%) initially increased the rate of growth, toxic symptoms were observed for 25% FA. Results from analysis of antioxidants (carotenoids, ascorbic acid, non-protein thiol, and free proline) revealed that these increased more in plants grown in 10% FA than in those grown in garden soil. Cysteine and malondialdehyde (MDA) content increased with increasing FA amendment. PCA also showed that all the antioxidants studied behaved similarly except cysteine, for which there was a close relationship with MDA content. Thus, the results obtained during this study revealed that V. radiata L. var. PDM 54 may be grown in 10% FA and/or contaminated agricultural soil.     

饭豆(Vigna umbellata L.)根瘤菌的分离及多样性

从生长在湖北省几种不同土壤中两类饭豆(Vigna umbellata L.)的根瘤中分离、纯化并通过结瘤试验筛选出26株饭豆根瘤菌；对这些菌株和来自其它种属的8个参比菌株的培养特性、生长速度、耐酸碱性、生长最终pH值、耐盐性、天然抗药性、碳源和氮源的利用及部分快生型菌株质粒图谱进行了系统的比较研究，并通过聚类分析得到数值分类树状图谱。结果发现，分离自不同类型土壤中的饭豆根瘤菌具有较大的多样性，在77％的相似水平上，形成了三大类群，群Ⅰ为慢生型菌群，群Ⅱ与群Ⅲ为快生型菌群，在80％相似水平上各群又可进一步划分为不同亚群，而且亚群中部分菌株的相似性与地理来源有相关性。图2表4参13。     

亚铵法造纸废液干粉对绿豆苗根系的AM真菌侵染及其地上部生物量的影响

通过温室盆栽试验,研究亚铵法造纸废液干粉对绿豆(Vigna radiate)苗根系的AM真菌侵染及其地上部生物量的影响。结果发现,添加适量造纸废液干粉可以加速AM真菌对绿豆苗根系的侵染;添加质量分数0.1%造纸废液干粉,出苗4周时绿豆苗根系的AM真菌侵染率比对照提高80%,出苗7周时地上部生物量比对照提高20%;添加质量分数0.2%~0.5%造纸废液干粉,绿豆苗根系的AM真菌侵染率和地上部生物量在出苗4周之后均不同程度低于对照。结果表明,添加质量分数0.1%左右亚铵法造纸废液干粉对AM真菌侵染绿豆苗根系和植株生长具有较好促进作用。     

Biochemical responses of Cr-tolerant and Cr-sensitive mung bean cultivars grown on varying levels of chromium

Biochemical investigations were carried out in Cr-tolerant and Cr-sensitive cultivars of mung bean (Vigna radiata L.) with different concentrations of hexavalent chromium (as K₂Cr₂O₇) in hydroponics culture. Seeds were germinated and grown in the presence or absence of chromium under controlled environmental conditions. Protein, pigment and enzyme analysis were conducted in both Cr-tolerant and Cr-sensitive cultivars of mung bean after 72 h of treatments. Chlorophyll and protein contents were reduced in Cr-sensitive cultivars more than those of the tolerant ones. The enzyme activity varied among the Cr-tolerant and Cr-sensitive ones. Activities of catalase, peroxidase, glucose-6-phosphate dehydrogenase and superoxide dismutase were greater in Cr-sensitive than tolerant cultivars.