Geographic Cline and Genetic Introgression Effects on Seed Morphology Variation and Germination Fitness in Two Closely Related Pine Species in Southeast Asia

There is still limited information on how genetic introgression impacts morphological variation and population fitness in long-lived conifer species. Two closely related pine species, Pinus kesiya Royle ex Gordon yunnanensis Franch. are widely distributed over Southeast Asia Yunnan province of China, with a large spatial scale asymmetric hybridization, form hybrid lineage, P. var. langbianensis, where their ranges overlap southeast Yunnan. We compared seed trait germination performance between hybrids parental species characterized environmental gradients to investigate the ecological evolutionary consequences introgression. found that width (SW) differed significantly among three pines, all traits were negatively correlated latitude associated mean temperatures driest wettest quarters. A higher was detected at low temperature, indicating they had better adaptability temperature stress than during process. Our results suggest factors shape phenotypic affects fitness. Therefore, assisting gene flow natural forest populations might facilitate adaptation climate change.