Genetic diversity and symbiotic efficiency of population of rhizobia of Phaseolus vulgaris L. in Brazil

The genetic diversity and symbiotic efficiency among indigenous rhizobia isolates obtained from native field with or without organic fertilization and superficial mineral fertilization were investigated. Eighty-six indigenous rhizobia were isolated from these fields using four common bean varieties as trap-host. The common bean varieties Mexico 309 and Rio Tibagi selected the most efficient rhizobia strains because they showed the best yields and N contents results. The genetic characterization of 36 rhizobia isolates was evaluated by using electrophoretic profiles of amplification products using primers ERIC1-R and ERIC-2. Our results demonstrated that besides the large diversity in the indigenous rhizobial community, the genotype of the trap-host probably influences the selection of the most efficient strains.