Characterization of indigenous rhizobia from wild legumes

Abstract

Rhizobia isolated from root nodules of wild legumes (Macroptilium lathyroides (L.) Urb, Phaseolus atropurpureus Moc & Sesse DC, Clitoria ternatea L., and Crotalaria verrucosa L.) were examined for cultural, biochemical, serological and symbiotic characters. The strains were characterized by their colony morphology, growth rate, alkali production, tolerance to acid or alkali, type of flagella, temperature sensitivity, resistance to antibiotics, utilization of different carbon sources, serological relatedness and ability to nodulate other host species. All of the strains had cultural characters consistent with the slow growing rhizobia of the cowpea group. Serological relatedness examined by the enzyme-linked immunosorbent assay (ELISA) technique showed that all of the 4 strains have antigenic homology to an isolate from a wild Arachis sp. and varying degrees of relatedness to cowpea rhizobia. All strains produced effective nodules on cowpeas and pigeonpeas but not on peanuts and kidney beans.