Diversity of bradyrhizobia from 27 tropical Leguminosae species native of Senegal

We isolated 71 slow-growing bacterial strains from nodules of 27 native leguminous plants species in Senegal (West Africa) belonging to the genera #Abrus$, #Alysicarpus$, #Bryaspis$, #Chamaecrista$, #Cassia$, #Crotalaria$, #Desmodium$, #Eriosema$, #Indigofera$, #Moghania$, #Rhynchosia$, #Sesbania$, #Tephrosia$, and #Zornia$ playing an ecological role and having agronomic potential in arid regions. The isolates were charaterised by restriction fragment length polymorphism (RFLP) analysis of PCR-amplified 165 rDNA and comparative SDS-PAGE of whole-cell proteins ; reference strains of the different known rhizobial species and groups were included as references. We conclude that these nodule isolates are diverse, and form several phylogenetic subgroups inside #Bradyrhizobium$. Nodulation tests performed on 5 plant species demonstrated host specificity among the strains studied. (Résumé d'auteur