卫矛科雷公藤属的谱系地理学研究

The genus Tripterygium Hook. f. (Celastraceae) has siginificant medicinal value. This genus distributed from mainland China, across Korean Peninsula and to Japan. Great morphological plasticity of the species, insignificance of genetic differentiation among species with overlapped distribution range, and scarcity of comprehensive phylogeography studies lead to the controversiality in taxonomic treatment of species and difficulties in understanding evolutionary issues such as speciation and formation of the distribution pattern. In this study, we will intensively harvest the population sample from its distribution range. The objectives of our study focus on: 1) construction of phylogeny of this genus using genetic varations from both chloroplast and nuclearDNA markers; 2) detecting the genetic diversity of populations, genetic structure and phylogeographical pattern using DNA variations and microsatellite analysis; 3) estimation of the divergence time of taxa by calibrating the molecular clock using fossils, and evaluation of the impact of climate fluctuations, fragmentation of land bridge, geographic barriers on currrent phylogeographic distribution pattern of Tripterygium. We expect to provide a case study and accumulate data for investigating the origins of the East Asian flora and the relationships of the flora of China mainland, Japan, Korean peninsula, and Taiwan.

卫矛科雷公藤属具有重要药用价值，为典型的中国-朝鲜-日本、中国-喜马拉雅分布类群。高度的形态可塑性，物种分布区的重叠区域内有大量中间型，遗传分化不显著，缺少深入全面的谱系地理学研究，使得该属种以及种以下阶元的分类学问题一直存在争议，缺乏对雷公藤属的物种分化、现有分布格局的形成等进化生物学问题的深入认识。本研究以居群为单位，在其分布区内全面取样，利用3个单亲遗传的叶绿体片段和3个双亲遗传的核DNA片段的序列分析，构建属内系统发育关系；采用DNA序列与微卫星标记的联合分析，检测该属居群的遗传多样性，揭示其群体遗传结构以及谱系地理格局；结合化石资料，推断属内各分支的分歧时间；结合地质历史资料，探讨气候的反复波动和陆桥的片断化等因素对雷公藤属现代谱系地理分布格局的影响，期望为阐明东亚植物区系的起源以及中国大陆与日本主大陆、朝鲜半岛、台湾岛等地区植物区系的关系等问题提供数据积累和实例参考。