ObjectiveThis paper aims to study the ecological adaptability of Pinus sylvestris var. mongolica in different geographical environments, to explore the relationship between genetic diversity and environmental factors, and to reveal the forest deterioration of Pinus sylvestris var. mongolica at population level.

MethodIn this paper, four Pinus sylvestris var. mongolica populations of Honghuaerji, Zhanggutai, Weichang and Yulin were selected as the study objects, the genetic diversity, genetic balance, genetic structure stability, genetic distance and the main factors affecting genetic variation in this four different populations were analyzed systematically and comprehensively by SSR molecular marker method.

ResultThe results showed that the genetic diversity of the four populations ranked as Yulin, Weichang, Zhanggutai, Honghuaerji; only the Yulin population was in accordance with the Hardy-Weinberg equilibrium, and the linkage disequilibrium points of the Zhanggutai population reached 128 pairs, deviating from Hardy-Weinberg equilibrium at P < 0.05 level; the genetic distance between Honghuaerji and Zhanggutai populations was closer, followed by Weichang population and the furthest was Yulin population; the four populations had relatively stable genetic differentiation, and were not prone to genetic differentiation; multiple regression analysis showed that the expected heterozygosity (He) had a significant negative correlation with geographic latitude (La) (r=-0.957), and the linear relationship was significant at P < 0.05 level.

ConclusionThe genetic diversity of Pinus sylvestris var. mongolica may decreased with the increase of latitude. This study improved the genetic diversity and genetic structure of Pinus sylvestris var. mongolica at the population level, clarified the genetic diversity inter or inner population, complemented the cause of forest deterioration, which provided a theoretical basis for the genetic resource protection and the introduction and popularization of Pinus sylvestris var. mongolica in large area.