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.

Microevolution, speciation and macroevolution in rhizobia: Genomic mechanisms and selective patterns.

Nodule bacteria (rhizobia), N-fixing symbionts of leguminous plants, represent an excellent model to study the fundamental issues of evolutionary biology, including the tradeoff between microevolution, speciation, and macroevolution, which remains poorly understood for free-living organisms. Taxonomically, rhizobia are extremely diverse: they are represented by nearly a dozen families of α-proteobacteria (Rhizobiales) and by some β-proteobacteria. Their genomes are composed of core parts, including house-keeping genes (), and of accessory parts, including symbiotically specialized () genes.

Diversity Indices of Plant Communities and Their Rhizosphere Microbiomes: An Attempt to Find the Connection.

The rhizosphere community represents an "ecological interface" between plant and soil, providing the plant with a number of advantages. Despite close connection and mutual influence in this system, the knowledge about the connection of plant and rhizosphere diversity is still controversial. One of the most valuable factors of this uncertainty is a rough estimation of plant diversity.

Rhizobia Isolated from the Relict Legume Represent a Genetically Specific Group within biovar .

Twenty-two rhizobia strains isolated from three distinct populations (North Ossetia, Dagestan, and Armenia) of a relict legume were analysed to determine their position within biovar (). These bacteria are described as symbionts of four plant genera , , , and from the Fabeae tribe, of which Vavilovia is considered to be closest to its last common ancestor (LCA). In contrast to biovar , bacteria from biovar () inoculate plants from the Trifolieae tribe.

Search for Ancestral Features in Genomes of bv. Strains Isolated from the Relict Legume .

is a relict leguminous plant growing in hard-to-reach habitats in the rocky highlands of the Caucasus and Middle East, and it is considered as the putative closest living relative of the last common ancestor (LCA) of the Fabeae tribe. Symbionts of belonging to bv. compose a discrete group that differs from the other strains, especially in the nucleotide sequences of the symbiotically specialised () genes.