中国栎属系统发育框架研究

The phylogeny and evolution of lineages having high species richness are research focus in biodiversity fields, which provides enormous significances for conservation of biodiversity. Quercus L. possesses high (oak) species diversity and most of them are important economic and ecological tree species in the Northern Hemisphere. However, researches of phylogeny and evolution on Quercus are always insufficient and biased due to the lack of genetic information of the Chinese oak resources. This project will focus on the Chinese oak species to construct the framework phylogeny at species and population levels with multiple genome-wide data (including chloroplast genome, transcriptome and reduced-representation genome). Based on the phylogeny of the Chinese oaks and with additions of global representative oak species, the project will also reconstruct the phylogeny of Quercus at the genomic level, and estimate its evolutionary history using molecular-clock models and coalescent theory and trace the potential associations between lineage/species diversification and past geographic and/or climatic changes. Our results will uncover the phylogeny of the Chinese oak species and fill the framework gaps in current phylogeny of Quercus with novel evidences from genomic data. Moreover, the results will reconstruct the evolutionary history and reveal the mechanism of diversification of Quercus, and provide possible models for research and conservation of biodiversity.

拥有较高物种多样性类群的系统发育关系和进化一直是生物多样性领域的研究热点。栎属物种多样性丰富，其属内的物种多是北半球重要的经济和生态树种，然而长期以来该属的系统发育和进化相关的研究由于缺少中国栎属资源的信息而存在不足。本项目拟以中国栎属物种为重点研究对象，采用多种类型的基因组水平的遗传数据（包括叶绿体基因组，转录组和简化基因组），从物种和群体水平上构建中国栎属的系统发育关系。以此为基础，加入国外分布的栎属代表物种重建基因组水平的栎属系统发育关系，并采用分子钟模型、溯祖理论等进化生物学方法对该属物种的进化历史进行研究，探讨栎属物种的多样化与过去地质、气候变化的联系。本项目的研究结论将揭示中国栎属物种的系统发育关系，填补全球栎属物种的系统发育空缺，并为之提供基因组水平的新证据。同时，研究结果将重建栎属物种的进化历史，揭示该属物种的多样化机制，为生物多样性的研究和保护提供可参考的范例。

栎属是木本植物中具有较高物种多样性类群之一，有重要的生态学和生物学价值。由于栎属物种表型变化丰富，种间基因渐渗频繁，该属内部系统发育框架尤其是中国栎属类群的系统发育关系长期存有争议。本项目搜集中国分布栎属56个物种样本，整合多基因片段、叶绿体基因组、转录组和简化基因组建库数据构建了可靠的中国栎属属内系统发育框架，同时基于化石记录信息和世系多样化模型重建了中国栎属类群的演化历史和物种多样化式样。研究结果揭示中国栎属由两个分支四个分组组成，包含新世界和旧世界起源的栎属类群。中国栎属属内组间分化和物种的多样化与亚洲地区地质、气候变动联系密切，在外界非生物因子驱动下演化出差异的物种生活史特征。尽管部分近缘物种之间存在基因交流，中国栎属物种可能在基因组水平演化出稳定遗传差异的潜能。本项目是对高多样性长命木本植物类群系统发育关系和演化历史的研究尝试，为北半球重要森林树种的起源和多样化提供遗传学证据。