Dissertation Research: A Systematic Study of Tribe Neillieae (Rosaceae)

[00:73041 .波特和奥]许多仅分布于东亚和北美温带地区的植物群长期以来一直引起植物学家的兴趣，在过去的两个世纪里，它们已成为许多分类学、生物地理学和进化论研究的主题。尽管对这类植物群的兴趣由来已久，最近也进行了一些系统发育研究，但它们的生物地理历史尚未得到很好的确立。Neillieae族，由Neillia， Physocarpus和Stephanandra三个分类学上困难的属组成，分布在东亚和北美东部和西部，通常在山区。Neillieae部落具有研究东亚和北美温带历史生物地理学的理想特征：该部落是一个得到强有力支持的自然类群，其分布可以在每个大陆的许多地区进行解剖，其物种数量较少（约25个）便于使用一系列现代系统发育方法分析各种数据。然而，尚未对该群体进行全面系统的研究。研究生Sang-Hun Oh在加州大学戴维斯分校Daniel Potter博士的指导下，正在利用形态学和分子数据研究Neillieae部落的系统发育关系。将分析Neillieae部落中所有物种的四个DNA区域，包括核基因组和叶绿体基因组，以及形态学特征，以估计最强大的系统发育框架。Neillieae部落的生物地理历史将使用这一系统发育框架结合当前分布模式和化石记录进行评估。还将提供一个具有反映Neillieae部落成员进化关系的健全分类系统的分类学修订。Neillieae部落的历史生物地理学将为理解东亚-北美断裂分布格局的形成方式和时间提供重要信息。此外，考虑到奈利亚属植物具有一定的园艺价值，本研究将为奈利亚属植物的种质筛选和观赏新品种的开发提供有价值的信息。最后，通过整合Neillieae部落的几个近亲，该项目产生的数据将有助于阐明蔷薇科的进化关系，蔷薇科是一个进化复杂且经济上重要的植物家族。

0073041Potter and OhMany plant groups distributed only in eastern Asia and temperate North America have long attracted the interest of botanists and have been the subject of numerous taxonomic, biogeographic, and evolutionary studies over the past two centuries. Despite this long history of interest and several recent phylogenetic studies of such plant groups, their biogeographic history has not yet been well established. Tribe Neillieae, comprising three taxonomically difficult genera, Neillia, Physocarpus, and Stephanandra, is distributed in eastern Asia and both eastern and western North America, usually in mountainous regions. Tribe Neillieae possesses ideal characteristics for studying historical biogeography of eastern Asia and temperate North America: the tribe is a strongly supported natural group, its distribution can be dissected into many areas in each continent, and its small number of species (ca. 25) facilitiates the analysis of a variety of data using a range of modern phylogenetic methods. However, no comprehensive systematic study of the group has yet been undertaken. Graduate student Sang-Hun Oh, under the direction of Dr. Daniel Potter at University of California, Davis, is studying phylogenetic relationships of the tribe Neillieae using morphological and molecular data. Four DNA regions, encompassing both nuclear and chloroplast genomes, for all species in tribe Neillieae will be analyzed along with morphological characters to estimate a maximally robust phylogenetic framework. Biogeographic history of the tribe Neillieae will be evaluated using this phylogenetic framework in conjunction with current distribution patterns and fossil records. A taxonomic revision with a sound classification system that reflects evolutionary relationships of the members of tribe Neillieae will also be provided. The historical biogeography of tribe Neillieae will provide important information relevant to understanding how and when the eastern Asian-North American disjunct distribution pattern developed. In addition, considering that plants of Neillieae are horticulturally useful, this study will provide valuable information for screening germplasm and developing new ornamental cultivars. Finally, by integrating several close relatives of the tribe Neillieae, data produced in this project will contribute to illuminating the evolutionary relationships within Rosaceae, an evolutionarily complex and economically important plant family.