黑木相思根瘤菌遗传多样性

Biodiversity of Rhizobia associated with Acacia melanoxylon grown in South China

摘要:

摘要:【目的】研究分离自广东、福建、江西等15 个地点的174 株黑木相思(Acacia melanoxylon)根瘤菌的遗传多样性。【方法】采用16S rDNA 限制性片段长度多态性分析(Restriction fragment length polymorphism，RFLP)和16S rDNA基因、持家基因(recA、atpD、glnII)系统发育分析的方进行研究。【结果】16S rDNA PCR-RFLP分析，在70%的相似性水平上，所有供试菌株分成9个类群;16S rDNA基因和持家基因系统发育分析结果基本一致，34株代表菌株主要分布在α-变形菌纲(Alpha Proteobacteria)的慢生根瘤菌属(Bradyrhizobium)、根瘤菌属(Rizobium)、中慢生根瘤菌属(Mesorhizobium)，并与Bradyrhizobium liaoningense、Bradyrhizobium betae、Bradyrhizobium cytisi、Rizobium multihospitium、Mesorhizobium plurifarium 亲缘关系较近。【结论】供试菌株被鉴定到属的水平，Bradyrhizobium、Rhizobium 或Mesorhizobium为优势菌群，证明了黑木相思根瘤菌具有丰富的遗传多样性。

Abstract:

Abstract:［Objective］This study aimed to investigate the genetic diversity of 174 isolates of symbiotic bacteria associated with Acacia melanoxylon obtained from 15 sampling sites in Guangdong，Fujian and Jiangxi provinces of China.［Methods］The 16S rDNA restriction fragment length polymorphism (RFLP) and phylogenetic analyses of the 16S rDNA and housekeeping genes (recA，glnII and atpD).［Results］In the 16S rDNA PCR-RFLP analysis，9 rDNA types were identified among the 174 isolates; Phylogenetic analyses based on 16S rDNA and housekeeping gene sequences indicated that 34 representative isolates belonged to the genus Bradyrhizobium，Rhizobium，Mesorhizobium in Alpha-Proteobacteria，and the most closely related strains are Bradyrhizobium liaoningense，Bradyrhizobium betae，Bradyrhizobium cytisi，Rhizobium multihospitium and Mesorhizobium plurifarium.［Conclusion］All of the isolates could be identified to general，and Bradyrhizobium，Rhizobium or Mesorhizobium could be the dominant microsymbiont． The microsymbionts associated with Acacia melanoxylon showed relative genetic diversity.