Genetic diversity of freshwater diatom algae populations Ulnaria danica (Kützing) Compère & Bukhtiyarova and Ulnaria ulna (Nitzsch) Compère

Abstract

Araphid diatoms of the genus Ulnaria are the dominant species in many freshwater ecosystems of Eurasia. Diatom populations are genetically heterogeneous and represent a combination of different genotypes. Genetic diversity is a necessary factor for adaptation to different environmental conditions and successful dispersal of species. We were analyzed the genetic diversity of the species Ulnaria danica and Ulnaria ulna using the example of monoclonal strains isolated from geographically distant water bodies of the continental part of Eurasia: Lake Ritsa, Lake Goluboe and Lake Baikal. Phylogenetic analysis of cox1 gene fragments of the studied strains demonstrated for the first time the heterogeneity of populations and the absence of geographic isolation for individual genotypes of the studied species. By analyzing the 18S rRNA marker genes, rbcL and cox1, the possibility of horizontal gene transfer between closely related species Fragilaria radians, Ulnaria acus, U. danica and U. ulna was established.