Abstract:

In order to characterize the diversity and phylogeny of rhizobium in Yunnan of China, 48 strains isolated from root nodules of Mimosa spp. and Desmodium spp. in 8 regions of Yunnan Province were studied with numerical taxonomy, 16S rDNA PCR-RFLP and 16S rDNA gene sequencing analysis. 23 genotype profiles were obtained from the fingerprinting of the 16S rDNA PCR-RFLP by four restriction endonucleases Hinf Ⅰ, Msp Ⅰ, Rsa Ⅰ and Hae Ⅲ. These strains were clustered into 4 branches at the similarity level of 70% by MVSP3.0 software. 16S rDNA sequencing revealed that branch Ⅰ belonging to the genera of Burkholderia, include 1 strain; branch Ⅱ belonging to the genera of Cupriavidus, include 5 strains; branch Ⅳ belonging to the genera of Rhizobium, include 29 strains; branch Ⅲ belonging to the genera of Stenotrophomonas with no reference strains. The analysis of 28 phenotypic characteristic of these strains showed that most of these strains had a high level resistance to saline, some strains could grow under severe environment such as high content ration of antibiotics (300 μg/mL) and high temperature (60℃). All the results demonstrated a high genetic and phenotypic diversity of rhizobium nodulating legumes of Yunnan Province.