Intrinsic multiple antibiotic resistance markers for competitive and effectiveness studies with various strains of mung bean rhizobia.

Ten strains of Rhizobium sp. with multiple antibiotic resistance markers were used for competitive and efficiency studies with mung bean var. ML 5. All the strains showed significant increase in grain yield and so also for nitrogenase activity except MO 5. Nitrogenase activity correlated very well with grain yeild. The compatibility of strains varied from 17 to 50%. The intrinsic multiple antibiotic markers for strain identification were found to be stable after passing through soil and host conditions and could be used for ecological studies. It was further revealed that the overall efficiency of a strain is the combined effect of characters like compatability, competitiveness and inherent capacity to fix nitrogen.