PLOIDY DETERMINATION OF SOME ARCTO-MONTANE WILLOW TAXA FROM THE COLLECTION OF BOTANICAL GARDEN, RUSSIAN ACADEMY OF SCIENCES, URAL BRANCH
S. O. Medvedeva1, O. V. Epanchintseva1, A. Yu. Teptina2
1Botanical Garden, Russian Academy of Sciences, Ural Branch, Yekaterinburg, Russian Federation
2Ural Federal University Named After First President of Russia B. N. Yeltsin, Yekaterinburg, Russian Federation
Keywords: Salix, hybridization, flow cytometry, genome size, DNA content
Abstract
The genus willow ( Salix L.), characterized by a widespread occurrence of polyploidy (ranging from 2n = 38 to 12n = 228) and chromosome number instability, is of significant interest to evolutionary biology and breeding. Arcto-Montane willows possess valuable adaptations to extreme environmental conditions and ornamental potential for landscape design; however, they remain cytogenetically understudied, particularly in Russia, where taxonomic and ecological research predominates. This work addresses this gap by applying a flow cytometry method to determine the ploidy level of 13 Arcto-Montane willows from the collection of the Botanical Garden, Russian Academy of Sciences, Ural Branch in the city of Yekaterinburg. The study employed an external standardization method, based on calculating the ratio of samples nuclear fluorescence intensity, followed by determining DNA content using internal standardization (with Solanum pseudocapsicum L., garden parsley ( Petroselinum crispum (Mill.) Fuss), and Pisum sativum L. as standards). The protocol was optimized by adding 2 % PVP to neutralize secondary metabolites. The results confirmed diploid level (2x) for creeping willow ( Salix repens L.), Pyrenean willow ( Salix pyrenaica Gouan), mountain willow ( Salix arbuscula L.), Salix saxatilis Turcz., and fishy willow ( Salix foetida Schleich. ex DC.), and tetraploid level (4x) for Salix caesia Vill. Specimens of retuse-leaved willow ( Salix retusa L.), Salix glauca var. callicarpaea ‘Haltia’, and Salix foetida × retusa were found to be octoploid (8x), while while gray willow ( Salix glauca L.) was decaploid (10x). The obtained data on ploidy and DNA content are important for taxonomy, hybrid identification, and the selection of perspective breeding material. Further molecular genetic studies are required to confirm the parental forms of the hybrid taxa.
|
