title: Distribution and diversity of rhizobia associated with wild soybean (Glycine soja Sieb. & Zucc.) in Northwest China.
abstract: A total of 155 nodule isolates that originated from seven sites in Northwest China were characterized by PCR-RFLP of the 16S rRNA gene and sequence analysis of multiple core genes (16S rRNA, recA, atpD, and glnII) in order to investigate the diversity and biogeography of Glycine soja-nodulating rhizobia. Among the isolates, 80 were Ensifer fredii, 19 were Ensifer morelense, 49 were Rhizobium radiobacter, and 7 were putative novel Rhizobium species. The phylogenies of E. fredii and E. morelense isolates in a concatenate tree (assembly of all housekeeping genes) were generally consistent with those in individual gene trees. However, incongruence was found in the phylogenies of the different genes of Rhizobium isolates, indicating that lateral transfer or recombination possibly occurred in these gene loci. Despite their species identity, all the isolates in this study formed a single lineage related to E. fredii in nodAand nifH gene phylogenies, which also indicated that the symbiotic genes were laterally transferred between different species. Biogeographic patterns were found at the species and strain genomic type levels, as revealed by BOXA1R fingerprinting, demonstrating that the evolution of rhizobial populations in different geographic locations was related to soil types, altitude and spatial effects. This study is the first to report that E. morelense, R. radiobacter, and Rhizobium sp. are microsymbionts of G. soja, as well as showing that the diversity of G. soja rhizobia is enhanced and new rhizobia have evolved in Northwest China.
authors: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors: Liang
authors: L
authors: Zhao
authors: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors: Miaochun
authors: M
authors: Fan
authors: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors: Dehui
authors: D
authors: Zhang
authors: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors: Ruiping
authors: R
authors: Yang
authors: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors: Feilong
authors: F
authors: Zhang
authors: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors: Lin
authors: L
authors: Xu
authors: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors: Xiuli
authors: X
authors: Wei
authors: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors: Yaoyao
authors: Y
authors: Shen
authors: State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China. Electronic address: weigehong@nwsuaf.edu.cn.
authors: Gehong
authors: G
authors: Wei
mesh_terms: D044822:Biodiversity; D002681:China; D004777:Environment; D005798:Genes, Bacterial; D020043:Genes, Essential; D023281:Genomics; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S; D012231:Rhizobium / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D013025:Glycine max / Q000382:microbiology*; D013559:Symbiosis / Q000235:genetics
chemical_list: D012336:RNA, Ribosomal, 16S
keywords: BOXA1R patterns; DAPC; MLSA; Phylogeny; RDA