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

真蓟属植物种类繁多，分类上存在问题，在世界范围内具有重要的生态和经济意义。物种间最小的遗传变异阻碍了Cirsium关系的解决，但现在可以通过鉴定三个高度可变的核基因区域来克服，这些区域在属内的精细水平上提供了系统发育信息。将通过比较三个核基因区域（G3pdh， B1启动子和组氨酸激酶）的DNA序列来研究真蓟的系统发育。有待检验的假设包括：(1)生态多样化的新大陆蓟是否构成一个自然群体？(2)新世界物种（尤其是加利福尼亚特有物种）是适应性辐射的好例子吗？(3)新大陆的蓟是由一个共同的欧洲或亚洲祖先产生的吗？(4)卷叶草与密切相关的心花属有区别吗？在卷草内的自然分组的决议也将用于取代普遍的，高度不自然的，属的分段分类。实现真蓟属植物的自然分类对于为未来真蓟属植物的基础和应用研究提供一个具有生物学意义的框架至关重要。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。本科生也将参与其中，并参与实验室研究。该项目还将涉及处于危险中的、不同种族的高中生，他们将被介绍到生物研究领域，并参与研究植物的种植。通过定义Cirsium中的自然物种群，这项研究将有助于生物防治研究人员选择新的药物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了解珍稀蓟的保护，更大的群体将可以在杰普森在线交流网站上获得结果，从而获得有关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.