A STUDY ON THE PREVALENCE OF BACTERIA THAT OCCUPY NODULES WITHIN SINGLE PEANUT PLANTS

ANGELINI, J.; IBÁÑEZ, F.; TAURIAN, T.; TONELLI, M.L.; VALETTI,L; FABRA, ADRIANA

CURRENT MICROBIOLOGY

SPRINGER

Año: 2011 vol. 62 p. 1752 - 1759

0343-8651

In this study, bacteria hosted in root nodules ofsingle plants of legume Arachis hypogaea L. (peanut) cvTegua Runner growing at field were isolated. The collectionof nodule isolates included both fast and slow growingstrains. Their genetic diversity was assessed in order toidentify the more frequently rhizobial strain associated tonodules from single plants. Molecular fingerprinting of 213nodular isolates indicated heterogeneity, absence of adominant genotype and, therefore, of a unique strainshighly competitive. Efficient nitrogen-fixing isolates wereidentified as Bradyrhizobium sp. by phylogenetic analysisof the sequences of their 16S rRNA genes. The geneticdiversity of 68 peanut nodulating isolates from all thecollected plants was also analyzed. Considering theirERIC-PCR profiles, they were grouped in eighteen differentOTUs for 60% similarity cut-off. Results obtained in this study indicate that the genetic diversity of rhizobiaoccupying nodules from single plant is very high, withoutthe presence of a dominant strain. Therefore, the identificationof useful peanut rhizobia for agricultural purposesrequires strongly the selection, among the diverse population,of a very competitive genotype in combination with ahigh-symbiotic performance.