Characterization of nodulating peanut rhizobia isolated from a native soil population in Córdobar Argentina

A total of 39 root nodule bacterial isolates were obtained from soils or Arachis hypogaea L. growing in fifteen different locations in Cordoba, Argentina. After authentication on homologous host species, the presence of nifD gene was analyzed, and their cultural and physiological properties were studied. About 46% of the isolates were fast-growers and produced an acid reaction in YEM medium. It was possible to differentiate this group from the slow growing isolates by their tolerance to environmental stresses (elevated concentrations of salt, acid pH and high temperature). The use of different carbon sources showed no differences among the isolates. Almost all the isolates were symbiotically effective with peanut and their nodulation ability in other legumes was also studied.