菊科蒿属龙蒿亚属的分类学研究

Artemisia is a taxonomically troublesome giant genus, among which taxonomy of its subgenus Dracunculus are much more complex. There are many confounded issues in the present taxonomy of the subgenus Dracunculus, including the lack of clearly defined boundary, confusing identities of a large number of species, and puzzling species delimination. The project will resolve these confusions by selecting appropriate molecular markers, reconstructing the phylogenetic relationships for Artemisia subgenus Dracunculus and all of its related taxa, acquiring new micromorphological, cypsela anatomical, cytological characters, recognizing symplesiomorphic features, thus clarifying its circumscription. Consequently, the project will clarify the true identities of its entire species and revise its taxonomy using morphological-geographical methods. Comprehensive evidences will be used to revise some confusing species of Artemisia subgenus Dracunculus. The researchers intend to study the character variations within and among populations of these complex species using multivariate statistical analysis methods. Ecological and geographical information will also be summarized to help delimitate the species. All these characters will be combined and evaluated together to get a reasonable taxonomy. This project will resolve the taxonomic problems of such an economically important taxon in the sunflower family. Furthermore, the project will promote the resolution of the similar problems in other taxa of the flowering plants and lay solid scientific foundations for effective utilizations of the plant resources in Artemisia subgenus Dracunculus.

蒿属是菊科植物的一个大属，具有重要的经济价值，但分类比较困难，存在不少混乱，是公认的疑难类群，其中尤以龙蒿亚属比较突出，主要是：亚属的界限需要进一步廓清、名实混乱和物种界限存在较大争议等。本研究将筛选合适的分子标记，重建龙蒿亚属及其近缘类群的系统发育关系，同时展开形态学、微形态学、瘦果解剖学和细胞学研究，以期发现一些新的分类学性状，寻找共近裔性状，从而澄清龙蒿亚属的范围；清理现存龙蒿亚属分类中的名实问题，循名责实；以地理－形态方法整理该亚属，对分类上比较困难的类群进行综合研究，以居群的概念为指导，借助多元统计的方法分析性状在居群内和居群间的变异，以期解决龙蒿亚属内复杂的性状变异，并综合分子证据和生态、地理证据确定物种界限。本研究的完成不仅可以解决菊科内部这样一个重要的疑难类群的分类学问题，有助于推动解决与之类似的有花植物其他类群的分类学问题，而且可以为龙蒿亚属植物的合理利用提供科学基础。

龙蒿亚属是蒿属下一个较大的群，主要分布在欧亚大陆，分类比较混乱，是蒿属植物分类的难点之一，主要是：亚属的界限模糊不清；亚属下种类亟待修订，包括名实混乱等。我们在欧亚大陆展开了广泛的野外考察和标本观察，研究了大量性状，结合移栽实验及统计分析，澄清了龙蒿亚属内部分种类的混乱，7个名称被处理为新异名。我们还展开了形态学、细胞学和基因组学研究，重建了龙蒿亚属及其近缘类群的系统发育树，无论在取样广度、研究性状数量，还是在研究方法上，都有所突破。综合各方证据，我们重新界定了龙蒿亚属的范围，提出了一个龙蒿亚属分类的新方案, 包含8个系，90个种。