Preliminary characterization of Rhizobium strains isolated from chickpea nodules

A total of 28 Rhizobium strains from chickpea nodules were characterized on the basis of morphological, cultural and biochemical characteristics. Most strains produced abundant extracellular polysaccharides, were tolerant to 0.5 M NaCI (53%) and a temperature of 40oC (75%). The majority of the strains showed an intrinsic resistance to the antibiotics (ìg ml-1) streptomycin (100), kanamycin (50), erytromycin (30), chloramphenicol (200) and penicilin (25). In vitro antibiosis assays indicated that Rhizobium strains from chickpea nodules exercised an antagonism against Ascocyhta rabiei the agent of ascocyhta blight disease of chickpea.