title: Genetic diversity of Rhizobium from nodulating beans grown in a variety of Mediterranean climate soils of Chile.
abstract: In spite of potentially being an important source of rhizobial diversity and a key determinant of common bean productivity, there is a paucity of data on Rhizobium genetic variation and species composition in the important bean producing area of Chile and only one species has been documented (Rhizobium leguminosarum). In this study, 240 Rhizobium isolates from Torcaza bean (Phaseolus vulgaris L.) nodules established in the highest bean producing area in Chile (33°34'S-70°38'W and 37°36'S-71°47'W) were characterized by PCR-RFLP markers for nodC gene, revealing eight banding patterns with the polymorphic enzyme Hinf I. The locality of San Agustín de Aurora in Central Chile (35°32'S-71°29'W) had the highest level of diversity. Isolates were classified by species using PCR-RFLP markers for 16S rDNA gene and were confirmed by sequencing an internal fragment of the 16S rDNA gene. The results confirmed the presence of R. leguminosarum and three other species of rhizobia nodulating beans in South Central Chile (R. etli, R. tropici and R. leucaenae). R. tropici and R. leucaenae showed the least genetic variation and were most commonly identified in acid soils, while R. etli was the most common species in slightly acidic to moderately alkaline soils, with higher levels of organic matter content. R. leguminosarum was identified in almost all soils, was the most genetically diverse, and was the most common, being documented in soils with pH that ranged between 5.3 and 8.2, and with organic matter content between 2.1 and 4 %.
authors.affiliation: Departamento de Producción Agrícola, Facultad de Ciencias Agronómicas, Universidad de Chile, Santa Rosa 11.315, La Pintana, Santiago, Chile, cbaginsk@uchile.cl.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Baginsky
authors.forename: Belén
authors.initials: B
authors.lastname: Brito
authors.forename: Rosita
authors.initials: R
authors.lastname: Scherson
authors.forename: Ricardo
authors.initials: R
authors.lastname: Pertuzé
authors.forename: Oscar
authors.initials: O
authors.lastname: Seguel
authors.forename: Alejandro
authors.initials: A
authors.lastname: Cañete
authors.forename: Cristian
authors.initials: C
authors.lastname: Araneda
authors.forename: Warren E
authors.initials: WE
authors.lastname: Johnson
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D002677:Chile; D002980:Climate; D014644:Genetic Variation; D006863:Hydrogen-Ion Concentration; D017351:N-Acetylglucosaminyltransferases / Q000235:genetics; D027805:Phaseolus / Q000382:microbiology*; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012231:Rhizobium / Q000235:genetics*; D053204:Root Nodules, Plant / Q000382:microbiology*; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D013559:Symbiosis
chemical_list: D001426:Bacterial Proteins; D012336:RNA, Ribosomal, 16S; D012987:Soil; D017351:N-Acetylglucosaminyltransferases; C060771:NodC protein, Rhizobiales