Study of Phytobeneficial Characterization and Biofertilizer Efficacy of Rhizobium Strain Isolated from Pulse Fields of Odisha

Abstract

Haphazard and indiscriminate application of chemical fertilizers has led to environmental contamination including deterioration of soil health. Hence it is very essential to inculcate biological agents in order to reduce the harsh effects of chemical fertilizer. The use of potent bacteria as a bio-fertilizer can improve the soil nitrogen status leading to enhanced soil health and improved productivity. Rhizobium provides a major source of nitrogen input in agricultural soils. On account of that, 64 bacteria were isolated and subjected to RT-PCR for nifH gene quantification to ascertain biological nitrification. From these 64, Seventeen potent PGP bacteria, isolated from different pulse fields, showing maximum PGP traits were studied further for nif H quantification. Out of 17, five were found to be possessing highest number of copy numbers of nifH gene indicating efficient nitrogenase activity. On molecular identification, it was revealed that except BS5JGS, rest all were belonging to the Enterobacteriaceae family. BS5JGS was found out to be Rhizobium sp., with an accession number assigned as OK602696. An array of organic acid production by the Rhizobium strain was estimated by HPLC, in which adipic acid was detected in highest concentration followed by tartaric acid, malonic acid, citric acid, ascorbic acid and phosphoric acid. The Rhizobial isolate was found to inhibit two most common fungal phyto-pathogens Fusarium oxysporum (ITCC 4998) and Rhizoctonia solani(ITCC 2060). It showed various phytobeneficial traits which imply it can be utilized as an effective biofertilizer for legumes and pulses as well as to maintain soil fertility and soil nutrient status.