Phylogeny and Evolution of the True Thistles, Genus Cirsium (Compositae-Cardueae)

蓟属（Cirsium）是世界北温带植物区系的重要组成部分，具有高度的多样性，在分类学上存在问题。最小的跨物种的遗传变异阻碍了解决蓟属的关系，但现在可以克服与识别三个高度可变的，核基因区域，提供系统发育信息，在细尺度的属内。通过比较三个核基因区域（G3pdh，B1启动子和组氨酸激酶）的DNA序列，将研究真蓟的系统发育。有待检验的假设包括：（1）生态多样性的新世界蓟构成一个自然群体吗？(2)新大陆物种（尤其是加利福尼亚特有种）是适应性辐射的好例子吗？(3)新大陆的蓟是来自欧洲还是亚洲的共同祖先？(4)蓟属与近缘属Carduus不同吗？在蓟属内的自然分组的分辨率也将被用来取代普遍的，高度不自然的，属的部分分类。实现蓟属的自然分类是至关重要的，为未来的基础和应用研究提供一个生物学意义的框架，真正的蓟。这项研究将对丰富加州大学伯克利分校的本科教育产生更广泛的影响。本科生将参加这项工作，并将参加实验室研究。该项目还将涉及处于危险中的不同种族的高中生，他们将被引入生物研究，并将参与种植研究植物。通过定义蓟属内的自然物种群，这项研究将有助于生物控制研究人员选择新的药剂来控制非本地杂草蓟。土地资源专业人员和普通公众将通过实地讲习班接受稀有蓟保护方面的指导，更多的人将可以在Jepson在线交换网站上获得结果，从而获得关于现代系统方法对了解区域植物多样性和分类的重要性的信息。

The true thistles (genus Cirsium) are highly diverse, taxonomically problematic, and ecologically and economically important components of north temperate floras worldwide. Minimal genetic variation across species has hampered resolution of relationships in Cirsium but can now be overcome with the identification of three highly variable, nuclear gene regions that provide phylogenetic information at fine-scale levels within the genus. Phylogeny of the true thistles will be studied by comparing DNA sequences from three nuclear gene regions (G3pdh, the B1 promoter, and histidine kinase). Hypotheses to be tested include: (1) Do the ecologically diverse New World thistles constitute a natural group? (2) Are the New World species (especially the Californian endemics) good examples of adaptive radiation? (3) Did the New World thistles arise from a common European or Asian ancestor? (4) Is Cirsium distinct from the closely related genus Carduus? Resolution of natural groupings within Cirsium also will be used to replace the prevailing, highly unnatural, sectional classification of the genus. Achieving a natural classification of Cirsium is critically important to provide a biologically meaningful framework for future basic and applied research on true thistles. This research will have the broader impacts of enriching undergraduate education at the University of California, Berkeley. Undergraduate students will be enlisted in the efforts and will participate in laboratory research. The project will also involve at-risk, ethnically diverse high school students, who will be introduced to biological research and will participate in growing research plants. By defining natural species groups within Cirsium, this research will aid biological-control researchers in choosing new agents for controlling non-native weedy thistles. Land resource professionals and the lay public will be instructed in the conservation of rare thistles by means of a field workshop, and a larger group will have access to results on the Jepson Online Interchange website, thereby obtaining information on the importance of modern systematic approaches to understanding regional plant diversity and classification.