Abstract
Genetic diversity and differentiation of six Populus tremula L. populations in the Ural mountains (Russia) were investigated using ISSR-markers. Analyses revealed relatively high genetic diversity and significant (p = 0.985) genetic isolation by distance of foothill and plain cis-Ural populations in the zone of forests with mixed coniferous and broad-leaved tree species. The genetic drift may be a factor that lead to comparatively low genetic variability and genetic singularities of isolated small populations of the aspen in dark coniferous taiga of the Ural mountains.