[Analysis of 16S rDNA sequence and DNA-DNA hybridization of rhizobia isolated from Indigofera sp].
Based on the previous studies on numerical taxonomy and SDS-PAGE of whole-cell protein, the rhizobia strains isolated from Indigofera sp. in loess plateau area of North-west China constituted a new cluster, the 16S rDNA sequence of representative strain SHL042 was tested, and the phylogenetic tree was produced. In this tree, the strain SHL042, R. tropici A, R. tropici B, R. leguminosarum, R. etli, R. hananesis, R. mongolense and R. gallicum constituted a branch of phylogenetic. Within this branch, the similarity values of 16S rDNA sequences were 95.4%, 95.5%, 96.3%, 95.8%, 96.3%, 97.9% and 97.7% respectively. The values were more than 95%. This indicated that these species should belong to the same genus. The values of DNA homology in the new cluster were all more than 80%, but the values between SHL042 and the strains of these species were less than 50%. Thus, the strain SH714 represented a new rhizobia species.