Genetic Divesity Of Rhizobia Isolated From Volcanic Geological Park And Rehai Park In Tengchong, Yunnan Provice,China

67 rhizobial strains isolated from different genera of legume plants of Uraria lagopodioides (L.) Desv., Kummerowia atriata(thumb.), Cassia mimosoide L., Desmodium sinuatum Bl., Glycine soja Sieb. et Zucc., Uraria lagopodioides (L.) Desv., Crotalaria mucronata Desv., Campylotropis delavayi (Franch.) Schindl., Campylotropis polyantha (Franch.) Schindl., Indigofera stachyoides Lindl. and Kummerowia atriata(thumb.), Cassia mimosoide L., Desmodium sinuatum Bl., Uraria lagopodioides (L.) Desv., Indigofera amblyantha Craib. were collected from Hot Spring Park and Volcanic Vent, respectively in Tengchong, Yunnan Provice. The genetic diversity of isolates were analyzed by ERIC-PCR,16S rDNA-AFLP, atpD, recA, Glnll, nifH and nodC, and the phylogeney of representative strains were performed by 16 S rDNA, atpD, recA, Glnll, nifH and nodC sequenences.The results of ERIC-PCR and 16S rDNA-AFLP showed that, there was high genetic diversity among these strains. The 16S rDNA PCR products were digested respectively with the restriction endonucleases Msp Ⅰ, Hae Ⅲ, Tap Ⅰ, Hinf Ⅰ. The isolates could be divided into 12 patterns by Hae Ⅲ,12 patterns by Hinf Ⅰ,14 patterns by Msp I,9 patterns by Tap I. The 16S rDNA genes of isolates could be divided into 18 genotypes. Analysis of ERIC-PCR divided the isolates into 3 genus, Bradyrhizobium(44 strains), Rhizobium(19 strains), and 4 strains were not clusterd with them, the genus of Bradyrhizobium were the main microsymbionts of isolates.According to the 16SrRNA PCR-RFLP and ERIC-PCR,32 represetative strains were chosen for sequence analysis.The phylogenic relationship construced by 16S rDNA gene full sequences shown that these rhizobial strains distributed into four branches of Rhizobium(7 strains), Bradyrhizobium(18 strains), Herbaspirillum(2 strains), Burkholderia(4 strains) and Labrys(1 strains). All of strains are clustered with Bradyrhizobium isolated from Kummerowia atriata(thumb.),The strain Q63-2 isolated from Cassia mimosoide L. and Q47-1 isolated from Indigofera stachyoides Lindl. in Hot Spring Park were clustered into Herbaspirillum, Q63-3 isolated from Cassia mimosoide L., Q8-2 isolated from Desmodium sinuatum BL, Q57-3 isolated from Indigofera stachyoides Lindl. in Hot Spring Park and H15-2 isolated from Indigofera amblyantha Craib., H5-1 isolated from Uraria lagopodioides (L.) Desv. in Volcanic Vent were clustered into Burkholderia, The strain of H17-2 isolated from Indigofera amblyantha Craib. in Volcanic Vent were clustered into Burkholderia. Sequence analysis of atpD, recA, Glnll genes, the results shown, the genus of Bradyrhizobium(18 strains) and Rhizobium(4 strains) grouping result were similar to 16S rDNA phylogeny tree, but the strain H17-2 clustered into Bradyrhizobium was not similar to 16S rDNA phylogeny tree. According to 16S rDNA and housekeeping genes phylogeny trees, the strains H10-1, H17-2, H8-1, H8-5, H19-2, Q99-1 clustered with B.japonicum, Q78-3, Q25-1, H23-2, Q94-4, Q2-2, Q1-1 clustered with B.elkanii, Q79-3, Q22-4, Q66-3、, Q66-6, Q49-3 clustered with B. liaoningense, Q50-4, Q57-1 clustered with R. leguminosarum, Q16-1 clustered with R. tibeticum, and strains Q8-2, Q17-2, Q8-3, Q47-1, Q63-1, Q63-2, Q63-3, Q57-3 were not clustered with representative stains. And some β-rhizobia of housekeeping genes were not amplified. Sequence analysis of symbiotic genes(nodC and nifH), there were many horizontal transfer of genes between different groups. All of the Bradyrhizobium stains phylogeny trees was similar to 16S rDNA and housekeeping genes phylogeny trees.