REVSYS: Phylogenetic, Biogeographic, and Revisionary Taxonomic Studies in Prunus (Rosaceae)

李属植物（蔷薇科杏仁亚科）由大约200种乔木和灌木组成，包括许多温带地区最重要的经济水果和坚果作物，如李子/李子、桃子、樱桃和杏仁，以及许多观赏物种和许多野生物种，因为它们被用作食物、木材和药物而具有民族植物学的重要性。李属植物在营养结构和生殖结构上表现出极大的形态多样性。该属分布在世界的北温带地区，在亚洲和美洲的热带地区也有代表。最近在蔷薇科和李属植物内部的分子系统发育研究对传统的杏仁核亚科的划分提出了质疑，并提出了李属植物需要一个修订的分类。此外，李属植物的物种划分是出了名的不清楚，以前没有系统的研究包括Pygeum组的充分代表，Pygeum组是旧大陆热带地区的一个大约40个物种的组。本项目是对李树进行全面系统的研究，其具体目标是：1)增加亚洲和美洲热带地区60-80种李树的植物标本室标本和DNA提取材料的收集；2)基于李属核和叶绿体基因组多个区域的核苷酸序列数据重建李属间的系统发育关系，同时也有助于解决李属与蔷薇科其他属的关系；3)在系统发育框架内研究形态特征的演化；4)对李属植物进行历史生物地理推断，并与分布在新旧大陆的蔷薇科中其他几个得到充分支持的分支进行比较，以评价李属植物是否存在重复的生物地理格局；5)提出了一种基于系统发育的李属分类新方法；6)修订50-60种热带亚洲李属植物的分类学，包括目前归为Pygeum属的所有物种。该项目由Dan Potter博士（加州大学戴维斯分校）与同事Jun Wen博士（史密森学会）和Joey Shaw博士（田纳西大学查塔努加分校）共同协调，将由一个具有互补专业知识和丰富经验的研究小组对一个大型、分类复杂且经济上重要的开花植物属进行严格的现代系统研究和新的分类处理。该项目更广泛的影响包括与这个经济上重要的群体的种质资源保护有关，培训一名东南亚研究生和一名美国博士后，以及开发由印度尼西亚波哥里安植物标本馆的研究人员提供的分子系统学短期课程。该项目的结果将通过科学出版物和互联网数据库和网站传播，包括对GenBank的贡献，为其他植物学家提供详细的分类信息，以及为教育工作者、学生和园艺学家提供的李树进化和系统学材料。这些研究产生的数据将对一个国际植物遗传学家联盟有价值，他们正在开发桃树，李子，作为玫瑰科基因组研究的模型。

The plant genus Prunus (subfamily Amygdaloideae of family Rosaceae) comprises roughly 200 species of trees and shrubs and includes many of the most economically important fruit and nut crops of temperate regions, such as plums/prunes, peaches, cherries, and almonds, as well as many ornamental species and numerous wild species of ethnobotanical importance because of their uses for food, timber, and medicine. Species of Prunus exhibit great morphological diversity of vegetative and reproductive structures. The genus is distributed throughout the north temperate regions of the world and also includes representatives in tropical regions of Asia and America. Recent molecular phylogenetic studies across Rosaceae and within Prunus have raised questions about the traditional circumscription of subfamily Amygdaloideae and have suggested that a revised classification for Prunus is needed. Moreover, species delimitation throughout Prunus is notoriously poorly understood, and no previous systematic study has included adequate representation of the Pygeum group, a group of about 40 species of the Old World tropics. This project is a comprehensive systematic study of Prunus, the specific objectives of which are: 1) to increase collections of herbarium specimens and material for DNA extractions of 60-80 species of Prunus from tropical Asia and America; 2) to reconstruct phylogenetic relationships across Prunus based on nucleotide sequence data from several regions of the nuclear and chloroplast genomes, while also helping to resolve the relationship of Prunus to other genera in Rosaceae; 3) to examine the evolution of morphological characters within the phylogenetic framework; 4) to infer the historical biogeography of Prunus and to compare it to several other well-supported clades within Rosaceae with distributions in the Old and New Worlds in order to assess whether or not there are recurrent biogeographic patterns in the family; 5) to propose a new phylogenetically based infrageneric classification for Prunus; and 6) to revise the taxonomy of the 50-60 tropical Asian species of Prunus, including all species currently classified in the Pygeum group. The project, a collaborative effort coordinated by Dr. Dan Potter (University of California-Davis) with colleagues Dr. Jun Wen (Smithsonian Institution) and Dr. Joey Shaw (University of Tennessee - Chattanooga), will provide a rigorous modern systematic study and new taxonomic treatments for a large, taxonomically complex and economically important genus of flowering plants performed by a team of researchers with complementary expertise and extensive experience with the group. The project's broader impacts include its relevance to germplasm conservation in this economically important group, training of a Southeast Asian graduate student and a U.S. postdoctoral fellow, and development of a short course in molecular systematics to be offered by the investigators at Herbarium Bogoriense in Indonesia. Results of the project will be disseminated via scientific publications and through internet databases and websites, including contributions to GenBank, detailed taxonomic information for other botanists, and materials on Prunus evolution and systematics intended for educators, students, and horticulturists. Data generated by these studies will be valuable to an international consortium of plant geneticists who are developing peach, Prunus persica, as a model for genomic studies in Rosaceae.