黄土高原地区大豆根瘤菌的遗传多样性和系统发育

Genetic diversity and phylogeny of soybean rhizobia isolated from the regions of Loess Plateau in China

摘要:

摘要：【目的】研究黄土高原地区大豆根瘤菌的遗传多样性和系统发育。【方法】采用BOX-PCR、16S rDNA PCR-RFLP、16S-23S IGS PCR-RFLP和16S rRNA基因序列分析方法对分离自我国黄土高原地区4个省的15个地区的130株大豆根瘤菌及部分参比菌株进行了遗传多样性和系统发育分析。【结果】BOX-PCR反映的菌株多样性最丰富，形成的遗传群最多，16S rDNA PCR-RFLP 方法在属、种水平上聚群较好，16S-23S IGS PCR RFLP反映的多样性介于BOX-PCR和16S rDNA PCR-RFLP之间，能够较好地反映出属、种和亲缘关系很近的菌株间的差异，3种方法聚类分析结果基本一致，可将所有供试菌株分为两大类群，中华根瘤菌属（Sinorhizobium）和慢生根瘤菌属（Bradyrhizobium）。从系统发育来看，供试的快生大豆根瘤菌为费氏中华根瘤菌（Sinorhizobium fredii），慢生大豆根瘤菌为日本慢生大豆根瘤菌（Bradyrhizobium japonicum）和辽宁慢生根瘤菌（Bradyrhizobium liaoningense）。 【结论】我国黄土高原地区大豆根瘤菌具有较丰富的遗传多样性，S. fredii优势种，慢生大豆根瘤菌仅占10%，同时，分离到2株B. liaoningense。

Abstract:

Abstract: [Objective] We investigated the genetic diversity and phylogeny of soybean rhizobia isolated from the regions of Loess Plateau in China. [Methods] We analyzed 130 soybean rhizobia isolated from 15 regions in 4 provinces of Loess Plateau through BOX-PCR, 16S rDNA PCR- RFLP, 16S-23S IGS PCR-RFLP and 16S rRNA gene sequencing. [Results] BOX-PCR, 16S rDNA PCR- RFLP and 16S-23S IGS PCR-RFLP were in good agreement with the results which showed that all strains tested ascribed to two groups: the genus of Sinorhizobium and Bradyrhizobium phylogenetically. The analysis of 16S rRNA gene of 5 representative strains indicated that they were related to type strains S. fredii, B. japonicum and B. liaoningense, homology coefficient with type strains was 100% respectively. [Conclusion] Soybean rhizobia isolated from the regions of Loess Plateau in China showed rich genetic diversity. S. fredii was the dominant species. Bradyrhizobium accounted for 10% of the strains tested only, of which, two strains were B. liaoningense.