北半球洲际间断分布木本植物类群——胡桃科系统发育基因组学与生物地理学研究

准确重建生物类群的系统发育是揭示生命体起源与演变动态、阐明生物多样性形成机理的基础。胡桃科是重要的阔叶林组成树种，间断分布于北美、欧洲和亚洲，少数种类延伸至美洲热带地区。其演化与分布格局复杂，孑遗成分多，化石资料丰富，是揭示北半球植物类群间断分布格局成因、探究北半球植物区系时空演变动态的关键类群。针对其系统发育关系不清、生物地理历史不明的问题，本课题基于良好的前期积累，拟采用强大的探针杂交捕获测序技术构建胡桃科高分辨率系统发育树，以之为基础推算各类群分化时间，分析物种多样化速率，重建祖先分布区，整合形态学、系统学、地理学等多领域研究成果，揭示胡桃科的时空演化历史。通过本课题的实施，可进一步验证北方热带植物区系等有关间断分布成因的假说，拓展对北半球区系演变的认知，研究成果也为全球气候变化背景下森林树种的保育实践提供基础和依据。

Accurately reconstructing lineage phylogeny is crucial for revealing the origin and evolution of organisms and elucidating the underlying mechanism of biodiversification. Juglandaceae, an important component of broad-leaved forest, areh disjunctly distributed in North America, Europe, and Asia, with a few species extending to tropical America. The complex pattern in evolution and distribution, abundant relic components of the Tertiary, and diverse fossil records make Juglandaceae a key group to reveal the underlying mechanisms of the intercontinental disjunct distribution pattern and the dynamics of the temporal and spatial evolutionary history of the Northern Hemisphere flora. Aiming at clarifying the unclear phylogeny and obscure biogeographic history, we will use the powerful Hyb-Seq method to reconstruct the phylogeny of Juglandaceae, estimate clade divergence time, analyze species diversification rate, and to reconstruct ancestral distribution range, and finally elucidate the biogeographic history of Juglandaceae. Our study will further test the hypotheses about the mechanisms of disjunct distribution such as the Boreotropical, broaden our understanding of the evolution of the Northern Hemisphere flora, and contribute to the conservation of woody plants under the background of global climate change.