The version of microevolutionary relationships between biotypes close to Elymus caninus (Poaceae) according to the sequencing of the nuclear gene GBSS1 (waxy)

A comparative study of the sequences of the GBSS1 gene fragment in accessions of species close to Elymus caninus:E. prokudinii, E. viridiglumis, E. goloskokovii, as well as a number of morphologically deviating forms (MDF) from the territoryof Russia and Kazakhstan was carried out. The StH-genomic constitution was established or confirmed in all studied taxa andMDF, and the microevolutionary relationships between species were assessed by constructing separate NJ dendrograms based onexons and introns together and exons only. Differences in the location of Y subgenomes in reference StY-genomic species on twotypes of constructed dendrograms were noted. Possible evolutionary reasons for these differences are discussed. A characteristicfeature of all taxa close to E. caninus is the presence of only St2clones of the St subgenome, which are closer in composition tothe North American ancestral line Pseudoroegneria spicata than to the Asiatic line ascending to P. strigosa. The reference Polishaccession E. caninus can_5274 is farthest from the Asian accessions in the St2subgenome, but closer to the diploid carrier ofthe St genome P. spicata. According to the levels of differentiation of the H subgenome, all putative relatives of E. caninus havevariants of the H1subgenome around the Asian diploid host Hordeum jubatum, while being divided into two distinct subgroups.Only the accessions of four reference species gravitate towards the North American species Hordeum californicum – the carrierof the H2gene variant. It should be noted that the gene variants of the Ural endemic E. uralensis are close to the main group ofE. caninus accessions in both subgenomes. Together with the results of sexual hybridization, this fact gives grounds to considerE. uralensis as closely related to the main group of taxa deserving the intraspecific rank of E. caninus s. l.