ABSTRACT

The present study characterizes twenty-one rhizobacterial strains isolated from root nodules of Vigna trilobata cultivars collected from various Andhra Pradesh, India districts. Rhizobacteria was isolated using selective medium Yeast Extract Mannitol Agar medium (Y.E.M.A.). All 21 strains were characterized based on colony morphology and biochemical characterization and identified up to species level by 16S rDNA sequencing analysis. Different genera of the bacteria are present in the root nodules of Vigna trilobata. Short random sequence primers amplify genomic D.N.A. in a process called random amplified polymorphic D.N.A. (R.A.P.D.), which were employed to assess genetic variation across isolated bacterial strains. Banding patterns were obtained via R.A.P.D. analysis of genomic D.N.A. from the isolates using five random primers, including OPA-4, OPA-9, OPA-11, OPA-12, and OPA-15. The R.A.P.D. profiles of twenty-one rhizobacterial isolates were compared separately to determine their differences by the occurrence of polymorphic D.N.A. fragments. PCR amplified of the D.N.A. isolated from twenty-one bacterial isolates yielded seventy amplified products, of which sixty-eight were polymorphic, and two were monomorphic. The investigation found that R.A.P.D. could differentiate between the strains very precisely. Characterizing and creating novel Rhizobium species can be aided by using molecular markers to investigate genetic diversity.

​

Keywords   Genetic diversity, rhizobia, Yeast Extract Mannitol Agar, Polymorphic D.N.A. fragments, R.A.P.D.