Сельскохозяйственная биология, 2011, № 3, с. 61-64.

УДК 631.46:579.64:575:577.2

TAXONOMY OF MICROSYMBIONTS OF Hedysarum AND Astragalus BASING ON RIBOSOMAL RNA GENES SEQUENCING

V.I. Safronova, E.P. Chizhevskaya, A.A. Belimov, E.A. Pavlova

The study of taxonomic positionn and symbiotic properties of 22 rhizobial strains from All-Russian collection of nonpathogenic microorganisms for agricultural purposes, which were isolated from root nodules of Astragalus sp., A. frigidus, A. uliginosus, A. falcatus, A. cicer and Hedysarum alpinum, was conducted. For identification the method of 16S rRNA gene (rrs) and 16S-23S rDNA (ITS region) sequencing was used. Three strains from Astragalus belonged to Mesorhizobium loti, one isolate was identified as Rhizobium leguminosarum. Two isolates from A. cicer most probably belong to new species within Mesorhizobium. Taxonomic position of Hedysarum microsymbionts and other isolates from Astragalus remains not clear, as the results of ITS and rrs sequencing do not confirm each other. Division of rhizobial isolates into phylogenetic clusters correlated neither with geographical origin of strains nor with species of plant which they were isolated from. There was not also a significant correlation between plant host range and taxonomic relationship of strains. These isolates form the wide cross inoculation group, including the leguminous plants from different tribes within the Galegoid complex (Galegeae, Hedysareae, Trifolieae, Loteae and Coronilleae).

Keywords: root nodule bacteria, Astragalus and Hedysarum microsymbionts, taxonomy, rrs and ITS sequencing.