Impacts of Natural Selection on Evolution of Core and Symbiotically Specialized () Genes in the Polytypic Species .

Nodule bacteria (rhizobia) represent a suitable model to address a range of fundamental genetic problems, including the impacts of natural selection on the evolution of symbiotic microorganisms. Rhizobia possess multipartite genomes in which symbiotically specialized () genes differ from core genes in their natural histories. Diversification of genes is responsible for rhizobia microevolution, which depends on host-induced natural selection.

Genetic relationship of Sinorhizobium meliloti and Sinorhizobium medicae strains isolated from Caucasian region.

Sinorhizobium meliloti and Sinorhizobium medicae are two closely related species of the genus Sinorhizobium showing a similar host range, nodulating leguminous species of the genera Medicago, Melilotus and Trigonella, but their phylogenic relationship has not been elucidated yet. In this paper we report the application of three different molecular markers, (i) RFLP of nodD genes, (ii) 16S-23S rDNA intergenic gene spacer fingerprinting and (iii) amplification fragment length polymorphism to S. meliloti and S.