title: Phenotypic and genotypic characterization of rhizobia from diverse geographical origin that nodulate Pachyrhizus species.
abstract: Legumes from the genus Pachyrhizus, commonly known as yam bean, are cultivated in several countries from the American continent and constitute an alternative source for sustainable starch, oil and protein production. The endosymbionts of these legumes have been poorly studied although it is known that this legume is nodulated by fast and slow growing rhizobia. In this study we have analyzed a collection of strains isolated in several countries using different phenotypic and molecular methods. The results obtained by SDS-PAGE analysis, LPS profiling and TP-RAPD fingerprinting showed the high diversity of the strains analyzed, although all of them presented slow growth in yeast mannitol agar (YMA) medium. These results were confirmed using 16S-23S internal transcribed spacer (ITS) region and complete sequencing of the 16S rRNA gene, showing that most strains analyzed belong to different species of genus Bradyrhizobium. Three strains were closely related to B. elkanii and the rest of the strains were related to the phylogenetic group constituted by B. japonicum, B. liaoningense, B. yuanmingense and B. betae. These results support that the study of rhizobia nodulating unexplored legumes in different geographical locations will allow the discovery of new species able to establish legume symbioses.
authors.affiliation: Centro de Formación e Investigación Agraria CIFA Las Torres y Tomejil, Alcalá del Río, Sevilla, Spain. dulcenombre.rodriguez@juntadeandalucia.es
authors.forename: Dulce N
authors.initials: DN
authors.lastname: Rodríguez-Navarro
authors.forename: María
authors.initials: M
authors.lastname: Camacho
authors.forename: Eduardo O
authors.initials: EO
authors.lastname: Leidi
authors.forename: Raúl
authors.initials: R
authors.lastname: Rivas
authors.forename: Encarna
authors.initials: E
authors.lastname: Velázquez
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis / Q000302:isolation & purification; D020369:Bradyrhizobium / Q000737:chemistry / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D004275:DNA, Ribosomal / Q000737:chemistry / Q000302:isolation & purification; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000302:isolation & purification; D004591:Electrophoresis, Polyacrylamide Gel; D020459:Genes, rRNA; D008070:Lipopolysaccharides / Q000032:analysis / Q000302:isolation & purification; D008969:Molecular Sequence Data; D029905:Pachyrhizus / Q000382:microbiology*; D010802:Phylogeny; D020543:Proteome / Q000032:analysis / Q000302:isolation & purification; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D019105:Random Amplified Polymorphic DNA Technique; D017422:Sequence Analysis, DNA
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D021903:DNA, Ribosomal Spacer; D008070:Lipopolysaccharides; D020543:Proteome; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S