title: Phenotypic and molecular fingerprinting of fast growing rhizobia of field-grown pigeonpea from the eastern edge of the Brazilian Pantanal.
abstract: The aim of this study was to evaluate the diversity of rhizobial isolates obtained from root nodules of pigeonpea plants grown at the eastern edge of the Brazilian Pantanal. The bacterial isolates were isolated from root nodules from field-growing pigeonpea grown in two rural settlements of the Aquidauana municipality. The bacterial isolates were characterized phenotypically by means of cultural characterization, intrinsic antibiotic resistance (IAR), salt and high incubation temperature tolerance, and amylolytic and cellulolytic activities. The molecular characterization of the bacterial isolates was carried out using amplified ribosomal DNA restriction analysis (ARDRA) and Box-polymerase chain reaction (PCR) techniques. In addition, the symbiotic performance of selected rhizobial isolates was evaluated in a greenhouse experiment using sterile substrate. The phenotypic characterization revealed that the bacterial strains obtained from pigeonpea root nodules presented characteristics that are uncommon among rhizobial isolates, indicating the presence of new species nodulating the pigeonpea plants in the Brazilian Pantanal. The molecular fingerprinting of these bacterial isolates also showed a highly diverse collection, with both techniques revealing less than 25% similarity among bacterial isolates. The evaluation of symbiotic performance also indicated the presence of microorganisms with high potential to increase the growth and nitrogen content at the shoots of pigeonpea plants. The results obtained in this study indicate the presence of a highly diversified rhizobial community nodulating the pigeonpea at the eastern edge of the Brazilian Pantanal.
authors.affiliation: Laboratório de Matéria Orgânica e Microbiologia do Solo, Departamento de Solos, Universidade Estadual do Mato Grosso do Sul, Aquidauana, MS, Brasil.
authors.forename: F M
authors.initials: FM
authors.lastname: Costa
authors.affiliation: Laboratório de Matéria Orgânica e Microbiologia do Solo, Departamento de Solos, Universidade Estadual do Mato Grosso do Sul, Aquidauana, MS, Brasil.
authors.forename: J A
authors.initials: JA
authors.lastname: Schiavo
authors.affiliation: Laboratório de Biologia Molecular e de Micro-Organismos, Departamento de Ciências do Ambiente, Universidade Federal do Mato Grosso do Sul, Corumbá, MS, Brasil.
authors.forename: M S
authors.initials: MS
authors.lastname: Brasil
authors.affiliation: Curso de Pós-Graduação em Agronomia-Ciência do Solo, Departamento de Solos, Instituto de Agronomia, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ, Brasil.
authors.forename: J
authors.initials: J
authors.lastname: Leite
authors.affiliation: Laboratório de Ecologia Microbiana, Embrapa Agrobiologia, Seropédica, RJ, Brasil.
authors.forename: G R
authors.initials: GR
authors.lastname: Xavier
authors.affiliation: Laboratório de Microbiologia do Solo, Embrapa Semiárido, Petrolina, PE, Brasil paulo.ivan@embrapa.br.
authors.forename: P I
authors.initials: PI
authors.lastname: Fernandes
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001938:Brazil; D036561:Cajanus / Q000382:microbiology*; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D010641:Phenotype; D012231:Rhizobium / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D017422:Sequence Analysis, DNA
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D004275:DNA, Ribosomal