title: Population genetic structure of Sinorhizobium meliloti and S. medicae isolated from nodules of Medicago spp. in Mexico.
abstract: We studied the genetic structure of 176 bacterial isolates from nodules of Medicago sativa, M. lupulina and M. polymorpha in fifteen sites distributed in three localities in Mexico. The strains were characterized by multilocus enzyme electrophoresis, plasmid profiles, PCR restriction fragment length polymorphism of 16S rRNA genes and of the intergenic spacer between 16S and 23S rRNA genes, and partial sequences of glnII, recA and nodB. Most of the strains were classified as Sinorhizobium meliloti, and a high genetic diversity was recorded. Six strains were classified as Sinorhizobium medicae, with no genetic variation. Phylogenetic and population genetic analyses revealed evidence of frequent recombination and migration within species.
authors: Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico. csilva@ccg.unam.mx
authors: Claudia
authors: C
authors: Silva
authors: Feng Ling
authors: FL
authors: Kan
authors: Esperanza
authors: E
authors: Martínez-Romero
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D004798:Enzymes / Q000235:genetics; D019143:Evolution, Molecular; D014644:Genetic Variation; D015810:Linkage Disequilibrium; D000455:Medicago sativa / Q000382:microbiology*; D008800:Mexico; D010802:Phylogeny; D010957:Plasmids / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D053204:Root Nodules, Plant / Q000382:microbiology; D020579:Sinorhizobium / Q000235:genetics*; D016962:Sinorhizobium meliloti / Q000235:genetics*; D012988:Soil Microbiology
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D021903:DNA, Ribosomal Spacer; D004798:Enzymes; D012336:RNA, Ribosomal, 16S