Application of repetitive extragenic palindromic (REP)-PCR and enterobacterial repetitive intergenic consensus (ERIC)-PCR analysis to the identification and classification of Japan and Thai local isolates of Bradyrhizobium japonicum, Shinorhizobium meliloti, and Rhizobium leguminosarum

Repetitive extragenic palindromic (REP)-PCR and enterobacterial repetitive intergenic consensus (ERIC)-PCR analysis was applied to the identification and classification of local isolates of 44 Bradyrhizobium japonicum, 7 Sino rhizobium meliloti, and 10 Rhizobium leguminosarum strains from Japan and T hai. Using genomic DNA of the 61 strains, both REP and ERIC primers induced reproducible PCR band patterns, although REP-PCR generated more bands and appeared to be more useful for distinguishing the isolates from each other. Using mixed matrix data from both REP- and ERIC-PCR data, it become possib le to distinguish all the isolates analyzed in this experiment from each ot her. When cluster analysis was applied to both PCR matrix data of 44 B. jap onicum isolates, only the REP-PCR dendrogram showed a grouping profile corr esponding to the exo-polysaccharide phenotype with it exceptions. When the matrix data of R. leguminosarum and S. meliloti mere subjected to cluster a nalysis, S. meliloti appeared to form a different subgroup from R. Legumino sarum in the dendrogram of REP-PCR data except for one strain. In the case of ERIC-PCR, isolates of R. leguminosarum from northern Thailand formed a s eparate subgroup from other R. leguminosarum and S. meliloti which were dis persed in the dendrogram. These data suggest that REP-PCR and ERIC-PCR were effective for the identification of individual isolates even though the is olates showed a wide genetic diversity and the same phenotype. When the dat a of the local isolates from Japan and Thailand were subjected to cluster a nalysis, REP- and ERIC-PCR analysis revealed different grouping characteris tics.