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

李(桃亚科，蔷薇科)植物包括约200种乔木和灌木，包括许多温带地区最重要的水果和坚果作物，如李子、桃子、樱桃和杏子，以及许多观赏植物和许多具有民族植物学意义的野生物种，因为它们被用作食物、木材和药物。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。该属分布于世界北温带地区，也包括亚洲和美洲热带地区的代表性植物。最近在蔷薇科和李属内的分子系统学研究对杏亚科的传统界限提出了质疑，并建议有必要对李属进行修订。此外，众所周知，对整个李属的物种划分知之甚少，以前没有一项系统的研究包含了约40个旧大陆热带物种的类群的充分代表性。本项目是对李属的系统研究，其具体目标是：1)增加来自热带亚洲和美洲的60-80种李的标本和DNA提取材料的收集；2)根据核基因组和叶绿体基因组多个区域的核苷酸序列数据重建李属之间的系统发育关系，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李的形态特征的进化；4)推断李属的历史生物地理，并将其与蔷薇科中其他几个有良好支持的分支进行比较，以评估该科是否存在重复的生物地理格局；5)提出一个新的基于系统发育的李属亚属下分类；以及6)修订50-60个热带亚洲李属的分类，包括目前归入Pygeum组的所有种。该项目由加州大学戴维斯分校的Dan Potter博士、Smithsonian Institution的Jun wen博士和田纳西大学查塔努加分校的Joey Shaw博士共同协调，将为一个大型、分类复杂且经济重要的开花植物属提供严格的现代系统研究和新的分类方法，由一组具有互补专业知识和丰富团队经验的研究人员执行。该项目的更广泛影响包括它与这个经济重要群体的种质保护的相关性，一名东南亚研究生和一名美国博士后研究员的培训，以及将由印度尼西亚Bogoriense植物标本馆的研究人员提供的分子系统学短期课程的开发。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的详细分类信息，以及为教育工作者、学生和园艺学家提供的关于李子进化和系统学的材料。这些研究产生的数据将对一个国际植物遗传学家联盟来说很有价值，他们正在开发桃子，将其作为蔷薇科基因组研究的模式。

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.