The ITS1-5.8S rRNA gene -ITS2 sequence variability during the divergence of sweet-grass species (gen us Glyceria R. Br.)

Abstract

Comparative analysis of the sequence ITS1-5.8S rRNA gene-ITS2 of the nuclear genome of 13 species of genus Glyceria, 4 species of Melica and a species of monotypic genus Pleuropogon showed that the species of the genus Glyceria have 3 haplotypes: 1) Haplotype A was found only in species of the subgenus Glyceria section Glyceria (G. septentrionalis, G. fluitans, G. declinata, G. occidentalis, G. notata, G. borealis, G. leptostachya) and in Pleuropogon sabinii; 2) Haplotype C is characteristic of the subgenus Hydropoa, section Hydropoa (G. grandis, G. х amurensis, G. triflora, G. maxima) and sect. Lithuanicae (G. leptolepis); 3) Haplotype B is found in the species of the subgenus Hydropoa sections Striatae (G. elata, G. striata, G. neogaea, G. canadensis), Scolochloiformes (G. alnasteretum, G. spiculosa) and G. lithuanica of sect. Lithuanicae. Species carring haplotype B are located at the base of the phylogenetic tree of the genus Glyceria and/or clustered with low bootstrap indices. On the phylogenetic trees inferred by the analysis of the sequences ITS and 5.8S rDNA both sect. Glyceria and sect. Hydropoa represented two sister monophyly branches. The species Pleuropogon sabinii belong to the branch of subgenus Glyceria as a sister monotypic branch to the branch of the sect. Glyceria.