#geneticpolymorphism

Abstract One of the most well-documented cases of successful plant invasion in Europe is the rapid spread of Himalayan balsam (Impatiens glandulifera Royle). Introduced from the Himalayas to Europe in the first half of the 19th century as an ornamental and nectar-producing plant, this species initially naturalized in the United Kingdom, from where it subsequently dispersed across the European continent. Despite the active invasion of I. glandulifera in Eastern Europe, the genetic diversity of its populations in this region has remained largely unexplored. In this study, we evaluated the variability of two chloroplast DNA (cpDNA) regions, trnS-G and rpl32-trnL(UAG), in I. glandulifera samples from Ukraine and compared the results with cpDNA variants from continental Europe, the United Kingdom, as well as from India and Pakistan. Our results reveal the widespread distribution of two distinct I. glandulifera haplotypes, T1-R1 and T2-R2, across continental Europe. These haplotypes differ in both cpDNA regions analyzed, and their divergence is inferred to have occurred within the species’ native range. Chloroplast DNA variation was found to be significantly higher in the native range than in the invasive range. The broad distribution of the two chloroplast haplotypes across Europe supports the hypothesis of multiple introductions of I. glandulifera into the continent. The uneven distribution of haplotypes T1-R1 and T2-R2 within Ukraine may indicate a founder effect.

Abstract Two species of the genus Galinsoga, G. parviflora Cav. and G. quadriradiata Ruiz and Pav., are among the most successful invasive plants causing significant damage to natural- and agroecosystems. Their natural distribution range extends from North to South America, and the adventitious part of the range includes all continents except Antarctica. Despite the practical importance of G. parviflora and G. quadriradiata, the genetic diversity of European populations of these species remains unexplored. In this study, ISSR markers were used to study Ukrainian populations of G. parviflora and G. quadriradiata and compared them with plants from Poland, Lithuania, and Portugal. The results obtained indicate the low genetic diversity (Shannon’s index I = 0.124) of G. quadriradiata populations, which is probably due to the small size of the original population introduced to the Old World from America. In contrast, the genetic diversity in G. parviflora populations is significantly higher (I = 0.254). Some genotypes of G. parviflora have a wide geographical distribution and, at the same time, different genotypes occur in the same area. The data obtained are in good agreement with the hypothesis that the main way of the invasion of Galinsoga species in the Old World was escape from botanical gardens. Among the samples examined, several forms of hybrid nature were identified, probably originating from hybrids between G. parviflora and G. quadriradiata, followed by subsequent backcrossing with one of the parent species.

Abstract The ITS1-5.8S-ITS2 (ITS1-2) region of the 35S rDNA is widely used for molecular barcoding and in the phylogenetics of plants. It is believed that, due to concerted evolution, all copies of 35S rDNA in eukaryotic genomes should be effectively homogenized. However, the existence of intragenomic polymorphism of the ITS1-2 region in plant genomes has recently been demonstrated, which may be a consequence of hybridization within or between species. In this study, the intragenomic polymorphism of the ITS1-2 region was evaluated using Illumina amplicon sequencing in accessions of two invasive species of the genus Reynoutria, R. japonica and R. sachalinensis, from Ukraine and Romania. Hybridization between these species can lead to the emergence of more aggressive invasive forms. The ITS1-2 sequences of the species studied were found to be represented by some major and minor subclasses/variants, indicating their incomplete homogenization. The number of major variants range from two in R. japonica to six in R. sachalinensis. The ITS1-2 variants that are widespread in the genome of one species may be present at low levels in another species, indicating possible interspecies hybridization. The obtained results show that the ITS1-2 intragenomic polymorphism must be taken into account when performing barcoding, reconstructing the phylogeny of low-level taxa, and for the identification of hybrid forms.

Keywords: 5S rDNA genetic polymorphism molecular evolution and phylogeny repetitive sequences pseudogenes Armeria Ceratolimon Goniolimon Limonium

Abstract The genus Muscari Mill. (Asparagaceae Juss.) includes about 80 species distributed in Eurasia, mainly in the Mediterranean region. Recent molecular phylogenetic studies have shown that the taxa belonging to this group form a monophyletic clade and are closely related. However, the phylogeny and status of some taxa of Muscari sensu lato remain controversial. So far, most phylogenetic studies of the genus Muscari have used almost exclusively Mediterranean plant material, while representatives of the genus from the Carpathian region remain unexplored. In this work, we used the sequencing of three regions of chloroplast DNA, psbA-trnH, trnT-L, and trnL-F, to clarify the phylogenetic relationships in the genus Muscari, to assess the genetic polymorphism and taxonomic status of Ukrainian populations of M. botryoides, as well as specimens of other Muscari species from the Carpathian region. According to the results of the phylogenetic analysis, the genus Muscari is a monophyletic group that includes three subgenera: Muscari, Muscarimia, and Pseudomuscari. Leopoldia species have been placed in the subgenus Muscari. Specimens of M. botryoides from Ukraine and Austria together with M. transsilvanicum from Romania and M. serpentinicum/M. sandrasicum from Turkey form the clade “Botryoides”, one of the three main clades identified in the subgenus Muscari. A significant genetic distance between Ukrainian specimens of M. botryoides, specimens of this species from other habitats, and other species of the genus Muscari allows us to consider the Ukrainian specimens of M. botryoides as a new, previously undescribed species. A comparison of the sequences of the investigated regions of the chloroplast genome revealed genetic differences between two groups of Ukrainian populations of M. botryoides, which can be interpreted as the existence of two intraspecific forms.