Characterization and Evaluation of Native Rhizobium of Groundnut (Arachis hypogaea L.) and Soybean (Glycine max L.)

The present investigation was conducted to characterize and evaluate native Rhizobium isolates of groundnut and soybean to enhance the Legume-Rhizobium symbiosis as well as increase sustainable crop production. In this connection, all the native isolates under study were characterized biochemically and tested with N-free sand culture in the glasshouse to select effective native Rhizobium isolates through proper screening. 10 isolates of each crop were collected from the culture collection bank of the Department of Agricultural Microbiology, Indira Gandhi Krishi Vishwavidyalaya Raipur (Chhattisgarh). Out of 10 isolates, 3 isolates of each crop were selected on the basis of their growth performance and the purity of the culture. The biochemical studies of selected isolates include starch hydrolysis, catalase, urease, citrate utilization, indole production, gelatine iron, and methyl red tests, which were further evaluated for nodulation and biological nitrogen fixation in groundnut and soybean under controlled conditions with four treatments for each crop and five replications. The experiment result revealed that the evaluation of native Rhizobium isolate no. 1185 of groundnut and isolate no. 1076 of soybean was found to be superior among all the rhizobial isolates taken for study. These isolates accumulated 1.24, 1.44 mg/plant extra amount of atmospheric nitrogen over un-inoculated control plants, respectively. Further, it can be concluded that these native isolates may be the most effective nitrogen fixers for groundnut and soybean over the control.