Taxonomic independence of the Siberian species Elymus lenensis (Poaceae) according to the GBSS1 (waxy) nuclear gene sequencing data

Abstract

In recent decades, contradictions between taxonomic and phylogenetic models in the systematics of vascular plants have clearly manifested themselves. To date, there are many species that have not been studied in culture and experiment or known only from herbarium specimens. The genus Elymus is the largest genus in the tribe Triticeae, declared a tertiary gene pool (GP-3) in relation to the main cereals. However, the genus contains many problematic species with unclear origins and relationships. One of these species is E. lenensis, described from the basin of the Lena River. The ambiguity of species descriptions made by different authors for the Siberian and Far Eastern regions is shown. The results of the analysis of the nucleotide sequences of the low-copy nuclear gene GBSS1 (waxy) in seven natural accessions similar in morphology to E. lenensis are presented. A dendrogram constructed using the “maximum likelihood” method is shown. A feature of all accessions close to E. lenensis is the presence of only St2 clones of the St subgenome, which are more related to the North American ancestral line of Pseudoroegneria spicata than to the Asian line descended from P strigosa (clones of the St2 subgenome). The general level of specificity of the GBSS1 gene sequences in comparison with the reference species is consistent with the conclusion about the existence of an independent species E. lenensis, especially considering the distance between accession locations.