RESUMEN
The variability of four microsatellite loci of chloroplast DNA was studied in 38 populations of Pinus sylvestris in the European part of Russia, Siberia, Kazakhstan, Transbaikalia and Mongolia. High variability was observed in all regions. In total, 152 haplotypes were identified. The level of population differentiation R(ST) was 2.1%. The differentiation of three geographical groups of populations (European, Siberian-Kazakhstan and Transbaikalian-Mongolian) was insignificant (R(CT) = 0.004%). At the same time, some rare haplotypes were found to be specific for a certain geographical region. Distribution of the rare haplotypes, which differentiated European populations from Asian populations and Mongolian and Transbaikalian populations from the Siberian, showed the independence of the history of these regions. This corresponds more to the hypothesis that the modern areal of Pinus sylvestris originated via settlement from many origins than to the hypothesized single center of the post-boulder-period of recolonization. The distribution of the pair differences between the individual specimens corresponded to the model of sudden population growth. The assessments of the age of this event for Pinus sylvestris (4.5-4.7 million years), which were obtained on the basis of this model, significantly exceeded the age of the quaternary period. Therefore, the revealed growth of populations is hardly due to the changes in flora related with the boulder-period, but rather mirrors the moment of the species formation.
