基于群体基因组学的华榛群体进化历史与局域适应机制研究

华榛是我国特有的古老经济林树种，其起源可追溯至晚第三纪，在长期演化的过程中形成了亚热带中高山间断分布的格局，群体间生境和表型差异显著。受区域环境变化和人为干扰的影响，华榛种群急剧衰退并处于濒危状态。然而，华榛的群体遗传特征仍缺乏系统评价，群体历史动态与环境演变的关系及其对异质环境的适应机制也尚未阐明。本项目拟在全面调查取样的基础上，通过简化基因组测序开展群体基因组学研究。基于全基因组遗传变异，精确解析华榛的群体遗传结构和遗传多样性，阐明其遗传变异分布格局；基于生态位和溯祖模型重建群体进化历史，揭示历史环境演变对华榛谱系分化的影响；以谱系间生态和表型显著分化的群体为材料，通过基因组扫描鉴定与环境适应相关的受选择位点并明确其代谢通路，阐明种群局域适应的遗传机制。研究结果对于深入理解华榛对环境时空变化的遗传响应与适应机制具有重要的科学意义，同时也可为自然资源的保护和遗传改良提供理论依据。

Corylus chinensis Franch. is an ancient economic forest species endemic to China, and its origin can be traced back to the late Tertiary. In the process of long-term evolution, C. chinensis has formed a disjunct distribution pattern in subtropical mountains, with significant differences in habitat and phenotype among populations. Affected by environmental change and human disturbance, populations of C. chinensis have declined sharply and are endangered. However, there is still lack of systematic evaluation on the population genetic characteristics of C. chinensis, and the relationship between its demographic history and environmental change, as well as its adaptation to heterogeneous habitats need to be clarified. Based on extensive sampling, population genomics will be conducted through RAD-seq technology to accurately detect the population structure and genetic diversity, and to clarify the distribution pattern of genetic variations. Then, the demographic history will be inferred using ecological niche and coalescent-based methods to reveal the influence of environmental change on lineage differentiation. Finally, candidate genes and metabolic pathways associated with environmental adaptability will be identified by genome scanning to elucidate the adaptative evolution of heterogeneous populations. The results not only have important scientific significance for understanding the genetic response and adaptation mechanism of C. chinensis to spatiotemporal environmental changes, but also provide a theoretical basis for the protection and genetic improvement of natural resources.