不同地域豇豆(Vigna unguiculata)根瘤菌的表型和遗传多样性  

Phenotypic and genetic diversity of cowpea rhizobia

作　　者：徐莉[1] 杨江科[1] 张伟涛[2] 袁天英[2] 周俊初[2] 

机构地区：[1]华中科技大学生命科学与技术学院,武汉430074 [2]华中农业大学农业微生物学国家重点实验室,武汉430070

出　　处：《生态学报》2007年第9期3655-3662,共8页Acta Ecologica Sinica

基　　金：国家科技部"973"重点基础研究资助项目(001CB1089);农学教学实验用微生物资源课题资助项目(2005DKA21208-6);华中农业大学农业微生物学国家重点实验室开放基金资助项目~~

摘　　要：豇豆根瘤菌既是豆科植物根际微生物的主要类群,也是重要的根瘤菌资源之一。通过最适碳/氮源、内源抗生素抗性和NaCl耐受性等表型特征和16S-23S Intergenetic Region(IGS)RFLP特征分析对分离自8个不同地域的52株供试豇豆根瘤菌的进行了表型和遗传多样性分析。供试菌株无论是在表型还是遗传型方面均具有丰富的多样性。根据IGS RFLP特征,供试豇豆慢生根瘤菌分为以下4个IGS类群:IGS-Ⅰ为豇豆根瘤菌的优势群体,在系统发育上相对独立;IGS-Ⅱ和IGS-Ⅲ的菌株分别属于Bradyrhizobium japonicum和Bradyrhizobium liaoningense;IGS-Ⅳ属于Bradyrhizobium elkanii。豇豆快生型菌株则分别归为IGS-Ⅴ和IGS-Ⅵ群,在分类地位上分别属于Sinorhizobium fredii和Rhizobium leguminosarum。不同地域的菌株在多样性方面具有明显的差异。分离自湖北红安的菌株仅与黑龙江德都具有一定的相似性,Jaccard系数为0.25,表现出地理隔离作用。来自黑龙江德都和广西武鸣的菌株的多样性最为丰富,其Simpson指数和Shannon-Wiener指数分别为0.667和1.243与0.593和0.961。Rhizobia are not only major microbial colonists of the rhizosphere of cowpea （ Vigna unguiculata ）, but also important root nodule symbionts. The present study was conducted with 52 cowpea-nodulating isolates collected from eight regions of China, and included phenotypic characterisation of optimal carbon/nitrogen source, intrinsic antibiotic resistance and NaC1 tolerance, as well as 16S-23S intergenic sequence （IGS） RFLP patterns. The strains tested showed abundant diversity. Slow-growing rhizobia were divided into four IGS RFLP groups. IGS-Ⅰ the dominant rhizobia group, was phylogenetically divergent from other cowpea rhizobia and reference strains. IGS-Ⅱ , IGS-Ⅲ and IGS-Ⅳ correspond to B. japontcum （IGS-V） province, , B. liaoningense and B. elkanii respectively. Fast-growing rhizobia appeared to belong to Sinorhizobium fredii or Rhizoblum leguminosarum （IGS-Ⅳ）. Strain diversity varied between regions. Strains from Hongan, Hubei all belonged to B. elkanii, and the Jaccard similarity coefficient with strains from Dedu, Heilongjian province,was 0.25. By contrast, strains from Dedu had rich diversity （ Simpson coefficient 0.66 and Shannon-Wiener coefficient 1. 243）, as did those from Lianyungang, Jiangsu Province （0. 593 and 0. 961 ）.

关 键 词：豇豆根瘤菌 表型 IGS 多样性 

分 类 号：S154.3[农业科学—土壤学] S643.4[农业科学—农业基础科学]