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In this paper, the 16S rDNA PCR-RFLP, numerical taxonomy nifH PCR-RFLP, nodC PCR-RFLP phylogenetic analysis (16S rDNA, recA, nifH, nodA gene sequence analysis), isolated from the Shaanxi-Gansu-Ningxia region in China 34 lespedeza rhizobia phylogenetic studies. 16S rDNA PCR-RFLP and sequence analysis showed that all tested strains digested types, divided into six kinds phylogenetic studies have shown that each restriction type represents the the R. gallicum, R. leguminosarum, S. meliloti, Mesorhizobium sp strain. , Bradyrhizobium sp., Sinorhizobium sp. 6 system development branch of the recA gene sequence analysis and 16S rDNA verify the correctness of the results of 16S rDNA sequence analysis. R. leguminosarum is the first time lespedeza rhizobia symbiont. The numerical classification results in a similar level of about 79%, the vast majority of tested strains can be clustered into two apparent groups. 89% similarity level is divided into three small groups, there is a certain similarity in the results of numerical taxonomy and 16S rDNA PCR-RFLP results. Physiological and biochemical traits test, the tested strains CCNWSX0705, CCNWSX0706, CCNWSX0703 the high salinity environment tolerated. The 6 strains resistance to heavy metal heavy metal tolerance tests were CCNWGS0255, CCNWNX0192, CCNWNX0194, CCNWSX0703 CCNWGS0251. nifH PCR-RFLP and sequence analysis showed that the phylogenetic relationships of nifH gene sequences reflect the phylogenetic relationships of 16S rDNA sequences similarity, found Lespedeza of Rhizobium species within the nifH gene diversity, R metastasis. leguminosarum and S. meliloti gene may exist in the horizontal direction between the genera fragment. nodC PCR-RFLP and sequence analysis showed that the great differences the nodC reflect the phylogenetic relationships of 16S rDNA sequence phylogenetic relationship further found that between R. leguminosarum and S. meliloti and R. leguminosarum and Bradyrhizobium sp. The gene fragment nodC between lateral transfer. The above results the following conclusions: Lespedeza symbiotic Rhizobium rich diversity; R. leguminosarum for Lespedeza new biotypes; the Lespedeza symbiotic and no apparent host specificity and In addition to R. gallicum may tend to exist in the north weakly alkaline soil, no obvious geographic distribution of differences in other groups of rhizobia; some of the tested strains with strong stress resistance; lespedeza rhizobia same species nifH and nodC The gene diversity; hold the same symbiotic genes found different kinds of lespedeza rhizobia.
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