不同地理环境下野豌豆根瘤菌的遗传多样性与共生进化研究  

Genetic diversity and co-evolution of Vicia rhizobia in different geographical environments

作　　者：张美玲[1] 朱博[1] 李旭[1] 鞠文庭[1] 韦革宏[1] 

机构地区：[1]西北农林科技大学生命科学学院微生物研究中心,陕西杨陵712100

出　　处：《西北农林科技大学学报（自然科学版）》2008年第12期192-198,共7页Journal of Northwest A&F University(Natural Science Edition)

基　　金：国家自然科学基金项目(30670372);全国优秀博士学位论文作者基金项目(200254);教育部新世纪优秀人才支持计划(NCET-04-0953);西北农林科技大学拔尖人才支持计划

摘　　要：【目的】研究西北部分地区不同地理环境下,野豌豆根瘤菌的遗传多样性及其共生进化间的关系。【方法】采用16S rDNA PCR-RFLP与16S rDNA全序列分析技术,对分离自陕西秦岭北麓红河谷、陕西南部汉中、甘肃沙漠绿洲带永昌混山窑、甘肃中部永登红城和新疆乌鲁木齐的5个不同地理环境(分别记做A、B、C、D、和E)的42株野豌豆根瘤菌,进行了遗传多样性和系统发育分析。【结果】测试根瘤菌共有6种基因型(Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ和Ⅵ),基因型Ⅰ根瘤菌在各个地理环境采样点均有分布,并且A地点分布的所有菌株均属于该基因型,基因型Ⅱ菌株分布于D和E采样地点,基因型Ⅲ菌株分布于B、C和D采样地点,基因型Ⅳ分布于E地点,基因型Ⅴ和Ⅵ测试菌株均分布于D地点。由16S rDNA全序列分析可知,基因型Ⅰ根瘤菌的代表菌株CCNWSX0050和基因型Ⅳ根瘤菌的代表菌株CCNWGS0055分别与Rhzobium leguminosarum的相似性为99.8%和99.7%;基因型Ⅲ根瘤菌的代表菌株CC-NWGS0062与Sinorhizobium meliloti的相似性为100.0%。【结论】中国西北地区野豌豆根瘤菌在分类学上属于Rhizobium leguminosarum根瘤菌和S.meliloti根瘤菌,野豌豆-根瘤菌的共生关系在不同地理环境中表现出差异性。[Objective] The study explored the genetic diversity and phylogenesis of Vicia Rhizobia in the northwest of China. [Method] 16S rDNA PCR-RFLP and 16S rDNA gene sequencing analysis were used to analyze the genetic diversity and co-evolution of the 42 vicia rhizobia grown in five different geo- graphical sites in Shaanxi, Gansu and Xinjiang （the sites designated A,B,C,D and E）. [Result] The RFLP analysis results of all strains indicated six bacterial genotypes designated Ⅰ , Ⅱ , Ⅲ ,Ⅳ, Ⅴ and Ⅵ. Strains in site A belonged exclusively to the group of genotype Ⅰ ,which were found in all the sites. And genotype Ⅱ strains were only found in sites D and E. Meanwhile sites B,C and D were of genotype Ⅲ. Strains of genotype Ⅳ were restricted to E,and genotypes Ⅴ and V1 to site D. Sequencing analysis of 16S rDNA revealed CCNWSX0050 of genotype Ⅰ and CCNWGS0055 of genotype Ⅱ shared 99.8% and 99.7% sequence homology with R. leguminosarum respectively,and CCNWGS0062 of genotype Ⅲ shared 100.0% sequence homology with S. meliloti. [Conclusion] The results showed that rhzobia, forming symbiosis with natural Vicia sepium in the northwest of China, belong to R. leguminosarum and S. meliloti, and symbiotic relationships between host plants and rhizobia in different geographical environments show diversity and nonrandom associations.

关 键 词：野豌豆根瘤菌 遗传多样性 共生进化 地理环境 

分 类 号：Q78[生物学—分子生物学] S154.381[农业科学—土壤学]