Genetic relationships among rhizopine-producing Rhizobium strains

The chromosome and symbiosis-related genotypes of rhizopine-producing strains of Rhizobium meliloti and R. leguminosarum cannot be identified on the basis of chromosomal characteristics. Rhizopine synthesis is related to certain symbiotic plasmid genotypes but is independent of the genome of the host plant. Rhizopine synthesis (mos) genes show more variations than rhizopine catabolism (moc) genes. Less divergence in the R. leguminosarum mos and moc genes shows that they have evolved after R. meliloti.