虎榛子属响应第四纪气候变化的分布迁移和新物种形成

项目名称： 虎榛子属响应第四纪气候变化的分布迁移和新物种形成

项目编号： No.41471042

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 天文学、地球科学

项目作者： 刘建全

作者单位： 四川大学

项目金额： 95万元

中文摘要： 第四纪气候变化导致我国植物物种分布变迁，已成为共识；但近缘物种是否由于分布变迁导致杂交、进而产生新物种的可能性还未得到验证。虎榛子属仅3种：滇虎榛子和居中虎榛子分布在青藏高原东部，而虎榛子分布在中国北方。已有的研究提出假设：青藏高原东部分布的居中虎榛子可能是由于第四纪冰期时，虎榛子南迁与滇虎榛子杂交产生的新物种。本项目拟利用个体和群体基因组数据，采用多种方法验证杂交物种形成假设或其它物种形成模型的可能性，同时检测每个物种有效群体大小变化所反映的响应气候变化导致的分布变迁和物种形成时间；然后，基于现有物种地理分布数据，利用生态位模型模拟检验第四纪冰期温度下降情况下虎榛子南迁与滇虎榛子接触和杂交的可能性。通过上述研究，验证和阐明虎榛子属响应气候变化的物种分布变化和新物种形成历史。研究结果对于深入理解气候变化背景下物种多样性的变化和保护这些重要生态资源具有重要意义。

中文关键词： 气候变化；分布变化；物种形成；生态位

英文摘要： It is well acknowledged that climatic oscillations of the Quaternary had caused the distribution changes of most plant species in China. However, it remains unclear whether such distribution changes of the closely related species might have leaded to the interspecific introgression and production of the new hybrid species. Ostryopsis comprises three species, O. davidiana in northern China, and O. nobilis and O. intermedia in eastern Qinghai-Tibetan Plateau. The available data hypothesized that O. intermedia originated from the interspecific hybridizations of the other two species when O. davidiana migrated southward and overlapped with O. nobilis. In this project, we aim to test these hypotheses by combining genomic data and niche modelling results. We will examine the statistic modelling of hybrid speciation versus other two possible speciation hypotheses and speciation time based on the available genomic data. We will use individual genome and population genomic data to infer changes of the effective population sizes and the corresponding distribution changes in response to the past climate changes. We will check whether distribution changes inferred from genetic data are consistent with those from niche modelling whether O. davidiana had migrated southward and contacted with O. nobilis during the Quaternary glaciation stages. All these results will deepen our understanding of the biodiversity changes and protections under the global climate changes in the future.

英文关键词： Climate change;distribution change;speciation;niches