Reproductive isolation and genetic differentiation of dry land and bog populations of Pinus sylvestris L. in Western Siberia and Russian Plain

Abstract

The results of large-scale interdisciplinary ecological and geographical researches (1973–2015 years), environmental gradients, reproductive isolation, genetic and phenotypic differentiation of Scots pine (Pinus sylvestris L.) populations of the dry lands and the adjacent bogs in Western Siberia and the Russian Plain have been generalized. The strong regime gradients of the physical, chemical, and especially hydrothermal factors of the pine populations edafotope on dry lands and adjacent high bogs in the sub-forest-steppe, in the middle and northern taiga (in a less degree) of Western Siberia have been revealed. The stable reproductive isolation of populations on the high bogs and (to a lesser extent) on the transitional bogs from the dry land ones, which is determinated by a later dates of the peat substrate heating, a differences in the phases of pollination-“flowering” (reception) of trees, and its increase in the general direction from the northwest to the southeast of the Russian Plain and the Western Siberia, has been determined. The significant genetic distances Nei (1978) and their gradients (bounds) between the dry land and adjacent bog populations in the south of forest zone (at the local population level), and lower gradients in the northern taiga subzones, as well as in transitional bogs have been found. For the first time the clear boundary between populations of P. sylvestris L. on the dry land and adjacent high bog (in the continuous areal) has been determined as a result of stationary palaeobotanical, ecological, phenological, morphological-anatomical-phenotypic and allozyme studies. An outline of hypothetical-deductive theory of genetic divergence of bog P. sylvestris populations from dry land ones in Holocene under the influence of the disruptive selection and the other factors of microevolution, which is proceed in the conditions of strongly contrasting environment and reproductive isolation has been substantiated through the generalization of research results and literature data.

Keywords

• Pinus sylvestris L.
• population
• dry land
• bog
• environmental factors
• allozyme analysis