Assessment of Phenotypic and Genotypic Diversity of Rhizobium Bacteria in Madhya Pradesh

Abstract

Rhizobia are usually defined as nitrogen-fixing soil bacteria capable of inducing the formation of root stem nodules on leguminous plants in which atmospheric nitrogen is reduced to ammonia, is catalyzed by nitrogenase for the benefit of the plant. In the present investigation, fifty strains of Rhizobium spp. (R1.........R50) from agricultural land of Madhya Pradesh were subjected to biochemical and genetic characterization. Fifty strains confirmed as Rhizobium spp. were used for further microbial diversity study. Percent G+C content of all the isolated strains was calculated by determining melting temperature of DNA (Tm). Tm of all the strains ranged between 94.3 to 95.7⁰C. However % G+C content of isolated strains ranges between 61.0 to 64.4 %. Furthermore, the pattern of genetic diversity was studied using known and established molecular biotyping methods. In the present observation isolated Rhizobium species were examined by REP-PCR, also the group differentiated with 25% similarity level into two groups in which one group with 100% similarity consists of R2 &R27 species. The least similar pattern with respect to the strains ignoring R2 and R27 maximum similarity upto 90% was seen between R21, R46, R23, and R48. On gel analysis of REP-PCR fingerprinting the bands appearing on gel also range between 100-900 bp, in the presence of 2% agarose. All restriction patterns of REP-PCR, fingerprints were coded in the binary form, and analyzed using NTSYS-pc package. A simple matching coefficient was calculated to construct a similarity matrix and the UPGMA algorithm was used to perform hierarchical cluster analysis and to construct a dendrogram.