title: Genetic diversity of fast-growing rhizobia that nodulate soybean ( Glycine max L. Merr).
abstract: The fast-growing Rhizobium sp. strain NGR234, isolated from Papua New Guinea, and 13 strains of Sinorhizobium fredii, isolated from China and Vietnam, were fingerprinted by means of RAPD, REP, ERIC and ARDRA. ERIC, REP and RAPD markers revealed a considerable genetic diversity among fast-growing rhizobia. Chinese isolates showed higher levels of diversity than those strains isolated from Vietnam. ARDRA analysis revealed three different genotypes among fast-growing rhizobia that nodulate soybean, even though all belonged to a subcluster that included Sinorhizobium saheli and Sinorhizobium meliloti. Among S. fredii rhizobia, two strains, SMH13 and HH303, might be representatives of other species of nitrogen-fixing organisms. Although restriction analysis of the nifD- nifK intergenic DNA fragment confirmed the unique nature of Rhizobium sp. strain NGR234, several similarities between Rhizobium sp. strain NGR234 and S. fredii USDA257, the ARDRA analysis and the full sequence of the 16S rDNA confirmed that NGR234 is a S. fredii strain. In addition, ARDRA analysis and the full sequence of the 16S rDNA suggested that two strains of rhizobia might be representatives of other species of rhizobia.
authors.affiliation: Instituto de Fisiología Vegetal, Universidad Nacional de La Plata, Cátedra de Microbiología Agrícola, Facultad de Ciencias Agrarias y Forestales, CC327 La Plata 1900, Argentina.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Saldaña
authors.forename: Virginia
authors.initials: V
authors.lastname: Martinez-Alcántara
authors.forename: José M
authors.initials: JM
authors.lastname: Vinardell
authors.forename: Ramón
authors.initials: R
authors.lastname: Bellogín
authors.forename: José E
authors.initials: JE
authors.lastname: Ruíz-Sainz
authors.forename: Pedro Alberto
authors.initials: PA
authors.lastname: Balatti
mesh_terms: D014644:Genetic Variation; D005838:Genotype; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012329:RNA, Bacterial / Q000737:chemistry*; D012336:RNA, Ribosomal, 16S / Q000737:chemistry*; D012231:Rhizobium / Q000145:classification / Q000235:genetics*; D013025:Glycine max / Q000382:microbiology*
chemical_list: D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S