title: Biodiversity and biogeography of rhizobia associated with common bean (Phaseolus vulgaris L.) in Shaanxi Province.
abstract: The biodiversity and biogeography of rhizobia associated with bean in Shaanxi Province were investigated. A total of 194 bacterial isolates from bean nodules collected from 13 sampling sites were characterized based on phylogenetic analyses of the 16S rRNA gene, the housekeeping genes recA, glnII and atpD, and the symbiotic genes nodC and nifH. Fifteen genospecies belonging to the genera Rhizobium, Agrobacterium, Ensifer, Bradyrhizobium and Ochrobactrum were defined among the isolates, with Rhizobium sp. II, Agrobacterium sp. II, E. fredii and R. phaseoli being the dominant groups. Four symbiotic gene lineages corresponding to Rhizobium sp. I, Rhizobium sp. II, R. phaseoli and B. liaoningense were detected in the nodC and nifH sequence analyses, indicating different origins for the symbiotic genes and their co-evolution with the chromosome of the bacteria. Moreover, the Ensifer isolates harbored symbiotic genes closely related to bean-nodulating Pararhizobium giardinii, indicating possible lateral gene transfer from Rhizobium to Ensifer. Correlation of rhizobial community composition with moisture, temperature, intercropping, soil features and nutrients were detected. All the results demonstrated a great diversity of bean rhizobia in Shaanxi that might be due to the adaptable evolution of the bean-nodulating rhizobia subjected to the diverse ecological conditions in the area.
authors.affiliation: State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, 11340 México, D.F., Mexico.
authors.forename: En Tao
authors.initials: ET
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Ya Juan
authors.initials: YJ
authors.lastname: Qiao
authors.affiliation: State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Shuo
authors.initials: S
authors.lastname: Jiao
authors.affiliation: State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Zhen Shan
authors.initials: ZS
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China. Electronic address: weigehong@nwafu.edu.cn.
authors.forename: Ge Hong
authors.initials: GH
authors.lastname: Wei
mesh_terms: D060054:Agrobacterium / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D001426:Bacterial Proteins / Q000235:genetics; D015373:Bacterial Typing Techniques; D001483:Base Sequence; D044822:Biodiversity; D020369:Bradyrhizobium / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D002681:China; D004269:DNA, Bacterial / Q000235:genetics; D014644:Genetic Variation / Q000235:genetics; D017351:N-Acetylglucosaminyltransferases / Q000235:genetics; D042041:Ochrobactrum / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D010088:Oxidoreductases / Q000235:genetics; D027805:Phaseolus / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D011938:Rec A Recombinases / Q000235:genetics; D012231:Rhizobium / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D053204:Root Nodules, Plant / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D014157:Transcription Factors; D010088:Oxidoreductases; C029130:nitrogenase reductase; D017351:N-Acetylglucosaminyltransferases; C060771:NodC protein, Rhizobiales; D011938:Rec A Recombinases
keywords: Bean; Biogeography; Diversity; Phylogeny; Rhizobia; atpD; glnII; nifH; nodC; recA