Gradient analysis of the chorogenetic structure of lowland and highland Scotch pine populations

Gradients of genetic distances (GGDs) between 26 adjacent cenopopulations o f Scotch pine (Pinus sylvestris L.) along the transects through the distinc t landscape-ecotopic isolation borders were analyzed graphically. The resul ts made it possible to reveal and quantitatively estimate gradients and bor ders of gene-pool structural patterns in populations of this species in the central part of Northern Eurasia. In lowland areas, the most distinct bord ers were found between pine populations growing on dry lands and in bogs (P ineta sphagnosa) in the forest zone of the Transural region, as well as bet ween the Arakaragaiskii and Amankaragaiskii island pine forests in the step pe zone (Northern Turgai). In highland areas (the Urals and the Carpathians ), the greatest GGDs were observed between low-mountain (about 600 m above sea level) and middle-mountain (850-900 m) populations. Analysis of GGDs is a promising gene-geographic method for determining population borders and studying the chorogenetic structure of species.