BRADYRHIZOBIUM LIAONINGENSE SP-NOV, ISOLATED FROM THE ROOT-NODULES OFSOYBEANS

Seventeen strains of extra-slowly growing (ESG) soybean rhizobia isola ted from root nodules of Glycine soja and Glycine mar growing in five provinces (Liaoning, Heilongjiang, Shanxi, Hubei, and Anhui) in the Pe ople's Republic of China were compared with 48 reference strains belon ging to the genera Bradyrhizobium, Rhizobium, and Agrobacterium by per forming a numerical analysis of 191 phenotypic features. Our results s howed that all of the ESG strains examined clustered closely in the ge nus Bradyrhizobium but were separated from Bradyrhizobium japonicum at the species level and that they could be differentiated from Rhizobiu m and Agrobacterium species at the genus level. On the basis of the re sults of our numerical taxonomy analysis, a genomic DNA G+C content an alysis, DNA-DNA hybridization experiments, a partial 16S rRNA sequence analysis, a serological analysis, an N and C content analysis, and an N/C ratio analysis of members of the three groups of soybean rhizobia , we propose the name Bradyrhizobium liaoningense sp. nov. for the ESG strains; the type strain of this species is strain 2281.