菊科蟹甲草属及其三个近缘属（兔儿伞属、小蟹甲属、华蟹甲属）的分子系统发育和生物地理学研究

项目名称： 菊科蟹甲草属及其三个近缘属（兔儿伞属、小蟹甲属、华蟹甲属）的分子系统发育和生物地理学研究

项目编号： No.31300169

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 生物科学

项目作者： 任琛

作者单位： 中国科学院华南植物园

项目金额： 24万元

中文摘要： 蟹甲草属、兔儿伞属、小蟹甲属、华蟹甲属是菊科千里光族款冬亚族4个近缘属，绝大部分种类（62种）产于我国。深入的形态学、细胞学以及初步的分子系统学研究均表明目前定义的蟹甲草属：（1）在一些重要性状（如叶形、小花颜色、染色体基数）上分化明显，极可能不是一个单系群；（2）与兔儿伞属、小蟹甲属、华蟹甲属之间的关系不清楚。本研究拟利用两个核糖体DNA片段（ITS、ETS），并筛选7个进化速率较快的叶绿体DNA片段和两个寡拷贝核基因，重建蟹甲草属及其近缘属的系统发育，并据以验证各属的单系性，评价其属间关系，构建其生物地理分化历史，从而解决蟹甲草属的范围及其界定问题，揭示一些重要性状（叶形、花色、子叶数目、染色体基数等）的进化式样以及类群的起源、物种形成式样和迁移扩散历史。本项目的开展对澄清东亚款冬亚族的属间关系、增加对千里光族性状的进化式样以及东亚植物区系分化的理解具有重要理论意义。

中文关键词： 菊科；生物地理学；蟹甲草属；系统发育；款冬亚族

英文摘要： Parasenecio, Syneilesis, Miricacalia, and Sinacalia are four genera of the Asteraceae (Senecioneae-Tussilagininae)endemic to Eastern Asia, with most of the species(ca.62 in total) occurring in China. Previous gross-morphological and cytological studies have suggested that (1) Parasenecio as currently circumscribed may not be a monophyletic group, and (2) its phylogenetic relationships with Syneilesis, Miricacalia, and Sinacalia remain unclear. Preliminary molecular studies concerning the phylogenetic relationships within the subtribe Tussilagininae,which were based on nuclear ITS and cpDNA trnL-F and ndhF regions of a small sampling of species, have also shown that Parasenecio is paraphyletic when Sinacalia is segregated as an independent genus of its own. In this project, we will perform a molecular analysis using two nrDNA (ITS and ETS) and seven fast-evolving cpDNA regions,and if necessary, also two single- or low-copy nuclear markers to test the monophyly of Parasenecio and its close allies, evaluate the phylogenetic relationships and construct their biogeographical diversification history (e.g.,their ancestral areas, vicariance and dispersal events, and divergence times).We will also analyze the variations of some important characters (such as leaf form, floret color,cotyledon number, and basic chromosome

英文关键词： Compositae；Biogeography；Parasenecio；Phylogeny；Tussilagininae