Diversity And Phylogeny Of The Rhizobia Isolated From The Root Nodules Of Pueraria Lobata Ohwi

The diversity and phylogeny of 43 rhizobial strains,which were isolated form the root nodules of Pueraria lobata Ohm in Pan Zhihua of Sichuan Province ,were investigated by the BOXAIR-PCR fingerprinting, 16S rDNA PCR-RFLP, 16-23SIGS PCR-RFLP, 16S rDNA,and GSII sequences. The results demonstrated that a high genetic diversity existed among these root nodule bacteria of Pueraria lobata Ohwi.Based on the dendrograms generated by BOXAIR-PCR, the strains gathered together with the similarity of 53%, and were divided into 28 groups with the similarity of 79.2%. In addition to the part of the strains and reference strains gathered together, the others formed independent groups, and the groups were closely related with the geographic distribution.The same strains used in BOXAIR-PCR were analyzed by 16S rDNA PCR-RFLP with four kinds of restriction endonucleases including HaeIII,MspI,HinfI and TaqI. Sixteen genotypes were identified. Some of the strains had similar restriction patterns with the reference strains of Rhizobium,Bradyrhizobium and Agrobacterium. The results of 16-23S IGS PCR-RFLP showed that with the similarity of 52% the strains were divided into 2 groups, and with the similarity of 90% the group 1 was divided into 13 groups .The results of 16S rDNA and GSII sequences analysis indicated that the representative strains could be classified into three groups of genus Rhizobium,Bradyrhizobium,Agrobacterium, respectively. But 16S rDNA sequencing homology was higher than GSII sequencing homology. GSII sequencing homology and 16S rDNA sequencing homology among the representative of strains are between 82.7%—90.5% and 87.7%—98.9%, respectively.