title: [Genetic diversity of rhizobia isolated from shrubby and herbaceous legumes in Shenmu arid area, Shaanxi, China].
abstract: Legume, with a strong resistance to the adverse environmental conditions, is one of pioneer plants in the desert region and plays an important role in the protection of the ecological environment. In this study, the symbiosis of rhizobia associating with shrubby and herbaceous legumes in Shenmu area, Shaanxi, China was characterized by the 16S rRNA PCR-RFLP and sequence analysis of involved genes. A total of 55 strains were isolated and purified, including 30 strains from the shrubby legume Amorpha fruticosa and Caragana microphylla, and 25 strains from herbaceous plants Astragalus adsurgens, Medicago sativa and Astragalus melilotoides. Results showed that there were 11 16S rRNA genotypes. The strains isolated from herbaceous legumes belonged to five genus including Mesorhizobium, Ensifer, Rhizobium, Phyllobacterium and Agrobacterium, which were very close related to M. huakuii, M. mediterraneum, M. robiniae, E. fredii, E. meliloti, R. indigoferae, R. radiobacter, P. ifriqiyense and Ag. tumefaciens through the phylogenetic analysis. The strains isolated from shrubby legumes belonged to Mesorhizobium, and they were very close related to M. huakuii and M. mediterraneum which were shared simultaneously by shrubby and herbaceous legumes. All of these indicated the choice of rhizobia by the two types of legumes in the arid area was different, and it might depend on the species of host plant and environmental factors.
authors.forename: Gang
authors.initials: G
authors.lastname: Nie
authors.forename: Wei-Min
authors.initials: WM
authors.lastname: Chen
authors.forename: Ge-Hong
authors.initials: GH
authors.lastname: Wei
mesh_terms: D027883:Astragalus Plant; D032602:Caragana; D002681:China; D007887:Fabaceae / Q000382:microbiology*; D014644:Genetic Variation; D000455:Medicago sativa; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012230:Rhizobiaceae / Q000145:classification*; D013559:Symbiosis
chemical_list: D012336:RNA, Ribosomal, 16S