全球气候变化对物种分布格局和种群动态历史有显著影响，同域分布物种、同属近缘物种、种下不同种群的历史种群动态对第四纪气候振荡的响应并非完全同步，至少部分呈现出因物种而异的特异性响应（idiosyncratic responses），但其机制仍不清楚。本课题以中国特有的新生代孑遗植物银杏避难所种群为研究对象，拟采用种群基因组重测序方法，结合最新发展的统计模型，在证实谱系分化式样的基础上，通过全面准确重建谱系/种群水平的种群动态历史和检测低温、干旱、病原菌响应的自然选择信号，检验不同避难所种群动态历史特异性响应更新世气候振荡的局部环境差异、寄主-病原菌共生协同进化变换假说。研究结果不仅可更全面认识银杏的种群进化历史、遗传变异格局的形成过程和机制，而且可以加深对全球变化背景下新生代孑遗森林植物濒危机制乃至水杉植物区系集中保存新生代孑遗植物原因的理解，为其保护与管理提供科学对策。

Global climate changes exert enormous impacts on species distribution and demographic history. Co-distributed species, congeneric species, and infraspecific populations may not respond synchronously to the Quaternary climate oscillations in terms of demography. The idiosyncratic response occurred in a substantial array of plant and animal taxa across the Northern Hemisphere whereas its mechanism remains unclear. We proposed to test the two hypotheses, i.e., regional environmental effects and changing balance of host-pathogen coevolved interactions by re-sequencing refugial population genomes of the Cenozoic relic tree species, Ginkgo biloba. Testable infraspecific lineages will be defined based on statistical confirmation of divergence patterns. Demographic trajectories will be reconstructed for each lineage and each studied populations. Selective signals imprinted by cooling, drying and pathogens will also be detected both between lineages and between populations. Our results will not only promote the comprehensive understanding on evolutionary history and causes and processes leading to the modern pattern of genetic variation of ginkgo, but also gain new insights into mechanisms of both endangerment of Cenozoic relic plants and their concentration in the Metasequoia Flora in the context of global climate changes. Such knowledge will inform and ultimately support effective conservation efforts.