基于目标富集测序解析东亚特有植物老鸦瓣属（Amana, Liliaceae）的物种形成及适应性演化

东亚具有丰富的物种多样性和高比例的特有物种，但该地区物种形成的过程和机制仍不甚清楚。申请人前期的野外调查、形态统计、系统发育分析和生态位分化研究已揭示出老鸦瓣属的物种组成及形态和生态位的显著分化，表明老鸦瓣属植物正是研究东亚地区物种形成和适应性演化的理想模型。本研究拟采用全长转录组测序（RNA-Seq）和目标富集测序（Hyb-Seq）技术，基于多位点的单拷贝核基因，重建老鸦瓣属的物种树；随后结合分化群体遗传学统计方法，计算老鸦瓣属物种分化过程中基因流的大小及时空分布，揭示老鸦瓣属物种形成的具体过程和时间框架；最后结合物种时空分布的生态模型，研究老鸦瓣属的物种形成和适应性演化的驱动因子和遗传基础。本研究可能是首个基于Hyb-Seq技术从群体水平对照研究广布种与窄域种物种分化的案例，其实施将为揭示东亚植物区系的物种形成和适应性演化机制提供新的证据。

East Asia is rich in species diversity and has a high level of endemism, yet the speciation processes and mechanisms in this region remain largely unexplored. Our previous field investigations, morphological statistics, phylogenetic study and niche differentiation analysis have resolved the phylogeny of East Asian tulips (Amana, Liliaceae), and showed significant differentiations in morphology and ecological niche among different Amana species. So that the genus Amana, which is endemic to East Asia, makes an ideal model for studying speciation and adaptive evolution. Combining full-length transcriptome sequencing and target enrichment sequencing (Hyb-Seq) techniques, this study aims to: 1) reconstruct the species tree of Amana based on multilocus single-copy nuclear gene; 2) reveal the specific process and time frame of speciation in Amana through calculating the spatial and temporal distribution of gene flow during the evolution process, and 3) clarify the driving factors and genetic basis of species’ differentiation. This study might be the first one to employ Hyb-Seq to study speciation at population level, by comparing widespread and narrow endemic species. Its implementation will provide new insights into the mechanism of speciation and adaptive evolution of East Asian flora.