PHYLOGENETIC RELATIONSHIPS OF UKRAINIAN ACCESSIONS OF LATHYRUS VENETUS (MILL.) WOHLF. AND L. VERNUS (L.) BERNH. BASED ON THE ANALYSIS OF THE psbA-trnH REGION OF THE CHLOROPLAST GENOME

Abstract

The member of the genus Lathyrus, L. venetus is listed in the Red Data Book of Ukraine as a vulnerable species. Estimation of L. venetus abundance is complicated by the prevalence of interspecies hybrids with L. vernus. These hybrid populations are often misidentified as populations of the L. venetus due to their morphological similarity. The study of genetic resources of L. venetus requires the use of molecular markers, both nuclear (to identify hybrid forms) and plastid (to determine the direction of hybridization) localization. One of the most promising chloroplast markers, the IGS region between the psbA and trnH genes, has not yet been sequenced for L. venetus and L. vernus. In this work, we evaluated the possibility of using the psbA-trnH region of the chloroplast genome to identify the parental forms of hybrids between L. venetus and L. vernus. We amplified and sequenced the psbA-trnH IGS for the collected in Ukraine accessions of L. venetus and L. vernus. For comparison, psbA-trnH sequences from the GenBank database were used that represent species from phylogenetically distant sections of the genus Lathyrus, as well as species of the Orobus section closely related to L. venetus and L. vernus. Based on the analysis of alignment of all sequences used, we found that the level of variability of psbA-trnH exceeds that of other chloroplast DNA regions used in phylogenetic studies of the genus Lathyrus. On the phylogenetic tree constructed by us, the genus Lathyrus forms a monophyletic group with high statistical support. The sequences analysis showed significant differences between the psbA-trnH IGS of L. venetus and L. vernus and confirmed the effectiveness of using this region for molecular identification of these species and for determining the direction of hybridization in the hybrid forms.