Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2021
Erindi/veggspjald / Talk/poster E2
Höfundar / Authors: Snædís H. Björnsdóttir (1), Ægir Þór Þórsson (2), Sæmundur Sveinsson (3), Kesara Anamthawat-Jónsson (1).
Starfsvettvangur / Affiliations: 1. Institute of Life and Environmental Sciences, University of Iceland; 2. The Icelandic Centre for Research (Rannís); 3. Icelandic Food and Biotech R&D (Matís).
Kynnir / Presenter: Kesara Anamthawat-Jónsson
Leymus Hochst. (lymegrass) is a genus of about 50 polyploid perennial grass species in the wheat tribe Triticeae. Lymegrass is an ecologically important plant due to the ability to bind soil and sand with its extensive rhizome system. Some species are forage grasses. Lymegrass has its distribution over the temperate regions of the Northern Hemisphere. In this study, we investigated three species from western North America, i.e., L. cinereus, L. innovatus and L. triticoides, in comparison with three species from Eurasia and Central Asia, i.e., L. chinensis, L. multicaulis and L. racemosus. We used the method of fluorescence in situ hybridization (FISH) to identify the Ns genome, with an aim to trace evolutionary relationships among these Leymus species. Ns genome belongs to the diploid genus Psathyrostachys Nevski, the ancestor of all polyploid Leymus species. Two Ns-specific repetitive sequence families were obtained: PshA (five 384-745 bp DraI clones from Ps. huashanica (China) and PsjD (six 570-625 bp ScaI clones) from Ps. Juncea (Russia). The sequence analysis showed over 90% homology within family. Southern blot experiments revealed specificity of PshA to American Leymus species, but PsjD to Eurasian/Asiatic species. FISH experiments revealed physical location of PshA and PsjD sequences on chromosomes, both on subtelometic heterochromatic regions. PshA hybridized to 22 sites on chromosomes of Ps. huashanica and the American Leymus species, whereas PsjD was localized to only 14 sites on chromosomes of Ps. juncea and the Eurasian/Asian species. We conclude that the American Leymus species under study are alloploid containing half of its Ns genomes deriving from Ps. huashanica, which has a very restricted distribution in China. On the other hand, Leymus species from Eurasia and Central Asia may have derived from Ps. juncea, which occurs in the same distribution range.