Geno- and phenogeographic analysis of Pinus sylvestris L. populations along the transect extending from the northern to southern boundary of the species range

Nei's genetic distances (Nei, 1972, 1978) between 12 Scotch pine (Pinus sylvestris L.) populations were determined using isozyme analysis. The gradients of these distances along the 1500-km meridional transect in the Transural Region and Northern Turgai from the pre-forest-tundra subzone (the Synya River basin) to the southern steppe (the Naurzumskii forest) were calculated. We discovered that the genetic distance gradients (GDGs) progressively increase in the direction from the northern boundary of the range to the southern boundary of the forest-steppe zone and sharply increase in the insular forests growing in the steppe zone. The results of cluster analysis and Mahalanobis distance gradients with respect to a set of morphological characters of the cones provide evidence that Scotch pine populations of the forest zone share somewhat the same gene pool, whereas the group of Scotch pine populations in the insular forests of Northern Turgai is obviously differentiated phenogenetically from the insular forests of the Tobol region, which grow farther to the north.