REU: Systematics and Phylogeny of Madagascan and African Dalechampia (Euphorbiaceae)

Dalechampia是一品红科（大戟科）的一个属，常见于亚洲、非洲和美洲的热带低地。虽然现在对新大陆物种的物种多样性、系统发育关系和授粉生物学有了很多了解，很大程度上是因为斯科特·阿姆布鲁斯特博士过去十年的研究，但对旧大陆物种的了解相对较少。Dalechampia被用作研究热带植物如何在特殊传粉媒介产生的选择压力下进化的模型系统。旧大陆的物种必须整合到这些研究中，以完成整个属的系统发育分析。此外，旧大陆和新大陆热带地区准确的植物区系清单（用于制定管理和保护决策）依赖于诸如Dalechampia等常见物种的可靠分类信息。在旧大陆，马达加斯加和非洲南部的Dalechampia种类最多。阿姆布鲁斯特博士将在该地区收集植物标本馆标本以及液体保存的材料，用于形态学和生化分析，包括分析由植物产生并被传粉蜜蜂使用的不寻常的树脂和芳香化合物。还将对授粉动物的行为进行观察。形态学数据将使用分支学方法进行分析，以确定可能的系统发育树，显示旧大陆分类群之间以及旧大陆和新大陆类群之间的关系。这些结果将完善Dalechampia的分类体系，揭示新旧世界物种进化过程中可能的迁徙路径，并确定这些植物中各种传粉机制的起源。

Dalechampia is a genus of vines of the poinsettia family (Euphorbiaceae) common throughout the lowland tropics in Asia, Africa, and the Americas. Although much is now known about the species diversity, phylogenetic relationships, and pollination biology of the New World species, in large part because of Dr. Scott Armbruster's studies over the last ten years, relatively little is known about Old World species. Dalechampia is being employed as a model system for the study of how tropical plants evolve in response to selective pressures generated by specialized pollinators. Old World species must be integrated into these studies to complete a phylogenetic analysis of the entire genus. Furthermore, accurate floristic inventories (used in making management and conservation decisions) of tropical regions of the Old World as well as the New depend on reliable taxonomic information for common species such as Dalechampia. In the Old World, Dalechampia is most diverse in Madagascar and southern Africa. Dr. Armbruster will collect herbarium specimens in this region along with liquid-preserved material, for morphological and biochemical analyses, including analyses of the unusual resins and fragrance compounds produced by the plants and used by pollinating bees. Observations of the behavior of pollinating animals will also be made. Morphological data will be analyzed using cladistic methods to determine likely phylogenetic trees that show relationships among Old World taxa and between Old and New World groups. These results will improve the classification system for Dalechampia, indicate likely migratory pathways in the evolution of Old and New World species, and determine the origins of the various pollination mechanisms found in these plants.