Abstract
In this research genetic diversity of 19 antagonistic bacterial strains were isolated from rice field contaminated with Rhizoctonia solani and Fusarium moniliforme. Based on morphological, biochemical, physiological and pathogenicity characteristics, total cellular protein profiles (SDS-PAGE) and PCR with specific primers the antagonistic strains were identified. The antagonistic strains of R.solani included B4, B6, B17, B18, B22, B24, B41 and B42 and that of F.moniliforme included F1, F6, F12, F15, F16, F18, F21, F24 were identified as Pseudomonas fluorescens and F14, F19, F32 and F35 were identified as Bacillus cereus. Out of fifteen RAPD primers, five primers were selected based on their ability to amplify all antagonistic strains. Twenteen strains were grouped based on RAPD analysis. Intra population gen diversity and distributed genetic diversity were assessed by POPGENE software. Nei’s genetic distance for A, B and C population is 0.22, 0.28 and 0.29 respectively. RAPD analysis revealed that strains B18 and F12 formed distinict group compared to other strains and showed maximum similarity with B24 and F18 strains. Other strains were placed in separated subgroups. Strains B41 and B6 showed maximum genetic distance. Molecular analysis using PCR based RAPD method is thus useful to differentiate such strains at the intra specific level.
