蒿属腺毛蒿组 (菊科-春黄菊族)的分类学研究

Artemisia sect. Viscidipubes (Asteraceae-Anthemideae) is mainly distributed in Sichuan, Xizang and Yunnan in southwestern China, with 21 species being recognized. Among them, 20 species have been reported in China. Due to striking similarity in their leaf size and leaf division as well as the small size of their capitula, species of this section are quite difficult to be distinguished from each other, which has led to frequent misidentifications of specimens in herbaria and inaccurate records of geographical distribution of taxa in literature. Moreover, some species seem morphologically not distinct enough to be worthy of recognition. Furthermore, the systematic position of A. sect. Viscidipubes within Artemisia and its relationship with its putative closest ally, i.e. A. sect. Albibractea, are also unclear because no material of the two sections have been included in previous molecular systematic studies. To address these problems, this project is intended to conduct a thorough taxonomic study on A. sect. Viscidipubes by using a multidisciplinary approach. After a survey of relevant literature, we will critically examine herbarium specimens and conduct intensive observations on living plants in the field and in-depth laboratory investigations to determine the taxonomic utility of all the macro- and micro-characters in this section, and then finish species delimitation. Moreover, we will reconstruct the phylogeny of A. sect. Viscidipubes to test its monophyly and clarify its systematic position within the genus and its relationship with A. sect. Albibractea. This project will provide a solid foundation for further comprehensive studies on the taxonomy and evolution of the whole Artemisia in China, and will also supply basic data for the utilization and conservation of the germplasm resources of the genus.

蒿属腺毛蒿组(菊科-春黄菊族)主要分布于我国四川、西藏和云南等省区，目前承认21种，我国记载有20种。由于叶片大小及叶分裂方式差异不大，头状花序均较小，该组植物彼此殊难区分，以致标本鉴定颇为混乱，一些种类可能不能成立，部分种类的地理分布记载存在明显错误。以往的分子系统学研究中没有将腺毛蒿组植物纳入分析，以致该组的单系性未得到分子系统学结果验证，其在整个蒿属中的系统位置及与其近缘组白苞蒿组的亲缘关系也不清楚。本项目拟利用多学科手段对该组展开全面的分类学研究。通过文献考证、标本室研究和野外考察，同时结合实验室研究，完成对该组的种类划分，然后综合利用多学科证据重建该组的系统发育，验证该组是否为单系群，并揭示该组在整个蒿属中的系统位置及其与白苞蒿组的亲缘关系。本项目的开展将为今后全面开展国产蒿属的分类和进化研究打下基础，同时为该属植物资源的保护和合理利用提供可靠资料。

利用多学科手段对蒿属腺毛蒿组（菊科-春黄菊族）进行了分类学研究。我们全面收集了蒿属腺毛蒿组乃至整个蒿属的分类学文献，建立了该属完善的文献数据库，研究了国内外主要标本馆的5万余份蒿属腺毛蒿组及其他组的标本，共采集蒿属植物700余号、3000余份标本及其所有居群的DNA材料和部分居群的活材料。形态学研究表明，茎毛被，叶分裂程度，叶裂片形状、宽窄，叶毛被，头状花序大小以及总苞毛被等是腺毛蒿组种级水平比较可靠的分类性状。对国产蒿属51种、6变种共137居群的染色体数目和46种、5变种共93居群的核型进行了研究（其中32种、5变种的染色体数目和核型为首次报道），确认了蒿属的主要染色体基数x = 9的观点，但目前还未发现蒿属内部各组之间染色体数目及倍性的关联。分子系统学研究表明目前定义的腺毛蒿组和白苞蒿组均非单系类群，即使将二者合并也不能构成单系，且其在艾蒿组中的系统位置也不确定。我们通过对蒿属腺毛蒿组的种类进行分类修订，最终承认该组共有17种、5变种。