Genotypic diversity of Ulnaria acus (K tzing) Aboal from Eurasia

Abstract

Abstract. Ulnaria a us is a cosmopolitan freshwater diatom. As a rule, diatom populations represent a combination of different genotypes. In early study, using a fragment of the rbcL gene of U. acus strains isolated from geographically distant regions, no significant genetic differences were found in the populations of this species. In this paper, we analyzed 41 strains isolated from different regions of Eurasia. Based on the analysis of the 18S rRNA gene fragment, it was shown that all strains form a single clade consisting of U. acus. Phylogenetic analysis of cox1 genes revealed that Eurasian strains of U. acus form three clades. Strains of U. acus from Lake Ritsa (Abkhazia) and Lake Matano (Indonesia) are not heterogeneous. Strains of U. acus isolated from Lake Baikal (Russia) and the r. Erdre (France) contained two clades and we can suggest that the genetic structure of the populations of this species is heterogeneous. All studied populations are conspecific taking into account their sexual compatibility of at least two generations.