Assessment of the variability of

A comparative study of taxa that are morphologically close to Elymus caninus, occurring in the territory of Russia and Kazakhstan, was carried out based on the ISSR molecular fingerprints. Data showed that the studied taxa are groups of individuals phylogenetically closely related to E. caninus. The assumption is confirmed that E. viridiglumis, as an Elymus species, has a polyphyletic origin as a part of microevolutionary processes in populations E. caninus s. l., possibly involving E. mutabilis. For the Caucasian endemic E. prokudinii and Kazakhstan endemic E. goloskokovii, the origin as result of introgression or spontaneous mutagenesis, i.e. a manifestation of the natural intraspecific polymorphism of E. caninus, is also assumed