ARTS: Collaborative Research: Understanding the relationships and radiation of Old World Croton (Euphorbiaceae)

这项研究将为更好地了解世界上最大的开花植物之一——大戟属（大戟科）的物种多样性和进化关系提供帮助。许多巴豆属植物具有重要的生态价值、药用价值，或被认为是濒危物种，但物种数量之多和在世界范围内的分布阻碍了以前充分了解该属系统分类学的努力。这项由波多黎各大学马亚圭斯分校和密歇根大学的研究人员进行的研究建立在先前对北美、中美洲和南美洲的Croton物种进行调查的基础上，现在的重点是为原产于亚洲、非洲和马达加斯加的大约450种Croton物种建立一个全面的系统发育和分类系统。本科研究人员和研究生，包括代表性不足群体的成员，将参与研究的各个方面，包括为波多黎各高中教师举办的植物生物学研讨会，向广大听众强调植物的重要性。本研究将利用野外、植物标本室和分子技术相结合的方法，调查非洲、亚洲和马达加斯加约450种巴豆的系统分类学。系统发育关系将利用至少10个核、叶绿体和线粒体标记的组合来重建，以提供必要的进化框架来研究Croton生物地理进化的速度和模式，重点是在整个旧世界的殖民和分散。巴豆不同物种的描述、图像和其他信息，包括该属的综合专著，将通过《生命百科全书》和《马达加斯加维管植物目录》的网页在网上免费传播。这项研究还将为马达加斯加物种建立一个DNA条形码数据库，以帮助识别这些物种。

This study will provide a better understanding of the species diversity and evolutionary relationships within one of the world's largest flowering plant genera, Croton (Euphorbiaceae). Many Croton species are important ecologically, used medicinally, or considered endangered, but the large number of species and worldwide distribution has hampered previous efforts to fully understand the systematics of the genus. This study by researchers at the University of Puerto Rico Mayaguez and the University of Michigan builds on a previous project investigating Croton species in North, Central and South America and now focuses on producing a comprehensive phylogeny and classification system for the estimated 450 Croton species native to Asia, Africa and Madagascar. Undergraduate researchers and graduate students, including members of under-represented groups, will be involved in all aspects of the study including plant biology workshops for high school teachers within Puerto Rico to highlight the importance of plants to a large and broad audience.This study will investigate the systematics of the estimated 450 Croton species in Africa, Asia and Madagascar using a combination of field, herbarium and molecular techniques. Phylogenetic relationships will be reconstructed using a combination of at least 10 nuclear, chloroplast and mitochondrial markers to provide necessary the evolutionary framework to investigate the tempo and mode of biogeographical evolution within Croton, with an emphasis on the colonization and dispersal throughout the Old World. Descriptions, images and additional information for different Croton species, including a comprehensive monograph of the genus, will be disseminated freely online through the Encyclopedia of Life and Catalogue of the Vascular Plants of Madagascar webpages. This study will also produce a DNA barcode database for the Malagasy species to help identify these species.