Genetic diversity and phylogeny of alfalfa nodulating rhizobia assessed by nifH and nodA genes

Abstract:The alfalfa (Medicago sativa L.) is broadly cultivated in various regions of Iran, but information on the genetic structure and phylogeny of the rhizobia nodulating this legume crop is scarce. The genetic diversity and phylogeny of 16 strains, isolated from root nodules of alfalfa was assessed by nifH and nodA genes sequencing. Results showed that, nifH and nodA fragments for Six strains could not be amplified and There were no nodules obtained from the plants inoculated with these strains as well. These findings suggest that they may be non-symbiotic and opportunistic bacteria that occupy root nodules. Based on the sequences of nodA and nifH genes, ten strains belonged to the S. meliloti.