沙冬青根瘤菌结瘤基因nodA PCR-RFLP分析

 利用结瘤基因nodA PCR-RFLP和nodA PCR产物序列分析技术,对36株分离自沙冬青根瘤菌菌株的共同结瘤基因nodA进行了遗传类型和系统发育关系分析。试验结果表明,36株根瘤菌nodA PCR-RFLP分析显示在80%的相似水平上聚为两个类群5个亚群;选取不同基因型代表菌株的nodA进行序列测定和系统发育关系分析表明,测试菌株CCNWNX0117、CCNWNX0068、CCNWNX0083、CCNWNX0062、CCNWNX0058与中慢生根瘤菌聚在一起,系统发育地位相近;测试菌株CCNWNX0089、CCNWNX0081、CCNWNX0064与中华根瘤菌聚在一起,有较高的序列相似性。本研究中nodA基因所揭示的沙冬青根瘤菌遗传多样性和系统发育关系说明沙冬青根瘤菌nodA基因遗传多样性较高,宿主结瘤范围较宽。

PCR-RFLP Analysis of Nodulation Gene nodA of Rhizobia from Ammopiptanthus mongolicus

Studies on relations between genotypes and phylogenic of 36 rhizobial strains isolated from Ammopiptanthus mongolicus were conducted by the methods of nodA PCR-RFLP and nodA sequencing. The results of PCR-RFLP clustering analysis showed that, at the similarity of 80%, the 36 strains are clustered with 2 groups within which there are 5 subgroups. The sequencing of the representative tested strains chosen from the identified different genotypes in the trials was conducted, and the analysis on phylogenic relations indicated that the tested strains of CCNWNX0117, CCNWNX0068, CCNWNX0083, CCNWNX0062, and CCNWNX0058 clustered with Mesorhizobium, and that the phylogenetic status is very close; meanwhile the tested strains of CCNWNX0089, CCNWNX0081, CCNWNX0064 clustered with Sinorizobium, the similarity of sequences is high. The studies indicated that the genetic diversity of nodA gene is relatively rich and has a broad adaptability to the potential hosts in nodulation.