Influence of root-knot nematode, Meloidogyne incognita (Kofoid & White) Chitwood infection on different plant growth parameters in Mungbean, Vigna radiata (L.) Wilczek

Root-knot nematode, Meloidogyne incognita (Kofoid & White) Chitwood, is a major threat to mungbean cultivation. The pest causes a significant reduction in plant growth parameters that ultimately results in loss of grain yield. The present study was carried out under glass house condition to study the effect of different inoculum load of root-knot nematode M. incognita on plant growth, nodulation and nematode development and nutrients status of Mungbean. The results revealed a progressive decline in plant growth parameters viz., fresh and dry shoot weight and shoot length with respect to increase in inoculum level. However, fresh and dry root weight showed the opposite trend. The fresh and dry shoot weight was decreased by 44% and 66%, respectively at 4 J2s/g soil. The chlorophyll content in the leaves also decreased with the increase of inoculum level from 100-6000 J2s/pot. Nutrients contents of the plant viz. N, P, K, Ca and Mg were significantly reduced in shoots while in roots these was increased with an increase of inoculum levels. Nodulation was affected by 80% at the highest inoculum level i.e. 6000 J2s/pot. Also leghaemoglobin, bacteroid content and nitrogenase activity was reduced progressively with increased levels of nematode inoculum. Thus, the root-knot nematode, M. incognita interferes with the process of symbiotic nitrogen fixation between mungbean host and rhizobium and that can affect the quality of produce.

Potential of Vigna radiata (L.) sprouts in the management of inflammation and arthritis in rats: Possible biochemical alterations.

Vigna radiata (Fabaceae) is an important pulse crop widespread throughout the tropics and warm temperature regions. In this study, we evaluated the in vitro anti-inflammatory and in vivo antiarthritic activity of Vigna radiata sprouts in rats. The in vitro anti-inflammatory activity was determined by membrane stabilization and protein denaturation method. Whereas, the antiarthritic activity of the ethanolic extract of the sprouts was evaluated by complete Freund’s adjuvant model with diclofenac sodium as the standard drug. Body weights, paw volume, biochemical parameters such as lipid peroxidation, total reduced glutathione, myeloperoxidase and lysosomal enzymes like cathepsin-D, N-acetyl β-D-glucosamindase and β-D-glucuronidase were estimated. Treatment with ethanolic extract of V. radiata exhibited significant membrane stabilization activity and protein denaturation activity, and significantly attenuated the biochemical changes induced by administration of complete Freund’s adjuvant. The findings of the present study suggest the possible role of Vigna radiata in the therapeutics of arthritis.

Isolation and gene expression analysis of Phospholipase C in response to abiotic stresses from Vigna radiata (L.) Wilczek.

Phosphatidylinositol (PtdIns) is a major phospholipid in eukaryotic cells. Many studies have revealed that the phosphoinositide (PI) signaling pathway plays an important role in plant growth and development. Phospholipase C (PLC) is reported to have a crucial role in the PI pathway. This work focuses on the isolation and investigation of PLC in response to abiotic stress factors in green gram. The PLC cDNA, designated VrPLC, encoding a protein of 591 amino acids was cloned and expressed in E. coli.The predicted isoelectric point (pI) and molecular weight were 5.96 and 67.3 kDa, respectively. The tertiary structure of the PLC was also predicted and found to be mainly composed of random coils. In addition, VrPLC expression analysis was performed under environmental stress and the results showed that the expression of VrPLC was rapidly induced in an abscisic acid independent manner in response to drought and salt stress. PLC expression was found to be up-regulated by SA and down-regulated by wound in leaf tissues; however, there was no significant difference in the expression of PLC in plants subjected to high temperature and H2O2. Our results suggest that a close link/relationship between PLC expression and stress responses in green gram.

Control of Seed Borne Fungi in Green Gram and Black Gram Through Bioagents.

Test the efficacy of fungal and bacterial antagonistic formulations were controlling the seed borne fungi in seed samples of green gram and black gram collected from Pulse Research Unit, Akola were used for laboratory test. Seed treatment with talc based formulation of Trichoderma viride at 4 g/kg, Pseudomonas fluorescens at 10 g/kg and Bacillus subtilis at 10g/kg bio agents were tested for their efficacy against seed-borne mycoflora to improve seed germination and also recorded significantly incidence of seed borne fungi. Among this three bio agents T. viride was found superior in controlling the seed borne mycoflora (86.90%, 88.00%) and also maximum seed germination was observed in T. viride (67.60%, 71.00%), shoot length (8.91cm, 11.5cm), root length (7.10cm,9.15cm) and seedling vigour index (1119,1466) in green gram and black gram respectively.

Standardization of DNA Extraction Protocol in Greengram (Vigna radiata (L.) Wilczek).

Green gram is a widely cultivated pulse crop rich in protein, high in vitamin-B content and essential aminoacids. It is easily digestable and low flatulence produced crop. The quality and quantity of DNA used for amplification by PCR is the key to reproducible results and success of genotyping. Especially, DNA purity is extremely crucial for obtaining clear and discriminate patterns. DNA extraction from Green gram is difficult due to presence of contaminants such as phenols. Therefore, the present study was under taken to obtain high quality and pure DNA in Green gram. With few modifications four different DNA extraction protocols were tried in the present study to obtain high quality and pure DNA viz., (i) Doyle and Doyle (1987), (ii) Method of Murray and Thompson (1980), (iii) Porebski et al.(1997), and (iv) Lin et al. (2001). Out of the four methods tried for DNA extraction, the method of Lin et al. (2001) was found most efficient, as the DNA obtained through this protocol was relatively pure which gave amplifying products in the PCR. The genotype used for the standardization was MGG -361.

Isolation of endophytic bacteria from green gram and study on their plant growth promoting activities.

A total of twenty five endophytic bacteria were isolated from green gram Vigna radiata (L.) plant. Four isolates which have shown better response for plant growth promoting effects on green gram plants were used as Plant Growth Promoting Bacteria (PGPB) in this study. It has been detected that up to 40% of the genomic 16S rRNA of isolated bacteria belongs to the Azotobacter genus. The result for phosphate solubilizing activities in NPRIB broth and Pikovskaya broth by UV-VIS Spectrophotometer (830 nm) showed that isolate FR was the best candidate in solubilizing of phosphorous showing 49.817Ppm with NPRIB broth and 53.534Ppm with Pikovskaya broth,respectively. Of all studied endophytes, isolates NL and NR have shown high nitrogenase activities and the activities being 2570.40 and 2108.00 n mole of C2H4 ml-1h-1 respectively. These strains will be selected for further use. The IAA production of all isolates was identified by FTIR spectroscopy and Spectrum for Crude IAA Extract of isolate FL is the best candidate for IAA production. The insoluble Potassium (K+) content in mica sample and the soluble K+ content by the inoculated samples were analyzed the atomic absorption spectrophotometric (AAS) method and isolates FL, FR, and NR were found to be good at decomposing insoluble potassium. These results indicated that the selected all four endophytic microbes could be excellent candidates for use as biofertilizer.

Effect of industrial effluent on the morphological parameters and chlorophyll content of green gram (Phaseolus aureus Roxb).

A pot culture experiment was conducted to study the effect of biomass power plant effluent on seed germination, seedling growth and chlorophyll content of green gram (variety LGG 460) have been estimated at different effluent concentrations and time intervals. The effluent is alkaline in nature (pH 8.5), odorless, and comprises of heavy metals such as Cr (0.071 mg l-1),Cu (0.014 mg l-1), Mn (0.036 mg l-1), Fe (0.05 mg l-1),Co (0.31 mg l-1), Ni (0.041 mg l-1),Cd (0.028 mg l-1), Pb (0.108 mg l-1) and Zn (6.73 mg l-1). The germination percentage of seed, seedling growth and chlorophyll content showed a gradual decline with increase in effluent concentration. It has been observed that at 25% effluent concentration, there is growth in the root length (3.50 cm seedling-1), an increase in shoot length (23.90 cm seedling-1) and total chlorophyll content (4.467 mg g-1 fresh weight) up to 20 days. After 20th day there is decline in all the parameters observed. However, at higher concentrations of the effluent, toxic effects were observed from 20th day. This suggests that the effluent can be used safely for green gram cultivation, only after proper treatment and dilution.