The phylogenetic diversity of 29 rhizobial strains nodulatingPhaseolus vulgarisin Iran was analysed on the basis of their core and symbiotic genes. These strains displayed five 16S rRNA-RFLP patterns and belong to eight ERIC-PCR clusters. The phylogenetic analyses of 16S rRNA,recAandatpDcore genes allowed the identification of several strains asRhizobium sophoriradicis, R. leguminosarum, R. tropiciandPararhizobium giardinii,whereas other strains represented a new phylogenetic lineage related toR. vallis. These strains and those identified as R. sophoriradicisandR. leguminosarumbelong to the symbiovar phaseoli carrying theγnodCallele distributed inP. vulgarisendosymbionts in America, Europe, Africa and Asia. The strain identified asR. tropicibelongs to the symbiovar tropici carried by strains ofR. tropici, R. leucaenae,R. lusitanumand R. freireinodulatingP. vulgarisin America, Africa and Asia. The strain identified asP. giardiniibelongs to the symbiovar giardinii together with the type strain of this species nodulatingP. vulgarisin France. It is remarkable that the recently described speciesR. sophoriradicisis worldwide distributed inP. vulgarisnodules carrying theγnodCallele of symbiovar phaseoli harboured by rhizobia isolated in the American distribution centers of this legume.
