第四纪气候变化对中国西北干旱地区物种地理分布及遗传多样性的影响仍不是很清楚。本项目选取古地中海孑遗濒危植物沙冬青属为研究对象，利用叶绿体DNA的IGS区、核糖体DNA的ITS区基因组序列及EST-SSR分子标记对沙冬青属种群的遗传多样性、遗传结构、谱系地理、系统发育关系及基因流等进行研究，并进一步利用古地质、古气候及末次冰期植被重建资料，推测沙冬青属在第四纪冰期的避难所及冰期后迁移路线；同时结合四种生态位模型（ENM）预测沙冬青属植物在过去、现在和未来气候变化条件下的空间地理分布范围以及对遗传多样性产生的影响。本项目的开展将进一步阐明第四纪气候变化导致的干旱化如何促进了中国西北地区物种分化及多样性的形成、生物避难所及多样性中心分布以及是否与其它地区具有相同或相反的植物谱系地理模式等科学问题。

The effect of Quaternary climate change on the geographical distribution of genetic diversity in arid northwest china is still not very clear. The genus Ammopiptanthus is an endangered shrub endemic to the ancient Mediterranean and endangered plant. In this project, the genetic diversity, genetic structure, phylogeography, phylogeny and gene flow of populations of genus Ammopiptanthus was investigated. The analysis was carried out based on nuclear sequence data from the internal transcribed specer (ITS) region of the ribosomal DNA and chloroplast DNA data intergenic spacer and EST-SSR markers. Using of the ancient geological, paleoclimatic data and revegetation information of the last glacial period, the inference was made that the possible glacial refuge and postglacial colonization routes of genus Ammopiptanthus plants in the Quaternary. Meanwhile, the four ecological niche models were used to predict the spatial geographic distribution and genetic diversity of genus Ammopiptanthus in the past, present and future climate change. Based on research, we attempted to address these questions: How was aridification resulting from climatic shifts promote the diversification and speciation in northwest china ? How were the refugia and biodiversity centers distributed? Were there common or contrary phylogeographical patterns as in other regions?