Abstract: Pinus koraiensis (Sieb. et Zucc.) is a coniferous tree species naturally distributed in northeastern China. However, the effects of gene flow on its genetic diversity and structure remain unclear. This study investigates these dynamics in seven populations using ten microsatellite markers. The results show a high level of genetic diversity within the populations (Ho = 0.633, He = 0.746). In addition, molecular analysis of variance (AMOVA) shows that 98% of genetic diversity occurs within populations, with minimal differentiation between populations (Fst = 0.009–0.033). Gene flow analysis shows significant migration rates between specific population pairs, particularly C-TH (87%), LS-Y (69%) and TH-LS (69%), suggesting genetic homogenization. Bayesian clustering (STRUCTURE) supports admixture and weak population differentiation. Environmental factors, especially temperature-related variables, significantly influence genetic patterns. Partial Mantel tests and multiple matrix regression show strong correlations between genetic distance and adaptations to cold temperatures (bio6 and bio11). Overall, this study emphasizes the robust genetic diversification and high migration rates in the populations of P. koraiensis and highlights their resilience. These results emphasize the importance of incorporating genetic and ecological factors into conservation strategies for sustainable forest management. This research provides valuable insights into the complex interplay of genetic variation, gene flow and environmental influences in forest tree species and improves our understanding of their adaptive mechanisms.

Key words: Pinus koraiensis, Gene flow, Migration rate, Genetic variability, Bioclimatic variables