近年分子系统学研究表明蔷薇科石楠属(Photinia Lindl.)和火棘属(Pyracantha Roem.)具有最近的亲缘关系。石楠属全球共60-65种，为东亚(中国、中南半岛、印度、喜马拉雅、日本)--墨西哥间断分布，包括Photinia s.s.、Pourthiaea和Stranvaesia；中国约54种，墨西哥7-9种。火棘属7-10种，中国9种，欧洲1种。该2属形态变异大，分类处理难。本项目拟对两属以及各疑难类群、复合群，广泛采集，利用微形态学、孢粉学、细胞学、分子系统学（用nrITS、PEPC、trnL-trnF、psbA-trnH、trnG-trnS基因）等方法，一揭示主要分类性状及其变异规律，完成经典分类学、地理分布区修订；二探讨疑难类群的微形态学、细胞学、孢粉学等特征；三阐明墨西哥分类群的地位；四完善系统演化研究，确定组、系及种间种下关系，建立两属新的分类系统。

The genera of Photinia Lindl. and Pyracantha Roem. in Rosaceae were proved to be having the closest relationship according to the molecular phylogenetic data in recent studies. The Photinia usually divided into three small genera by different scholars according to different standards including Photinia, Pourthiaea and Stranvaesia, is an East Asian (China, Indo-China Peninsula, India, Himalaya,Japan）-- Mexico disjunct distribution genus with about 60-65 species in the world, which 50-54 species were recorded in China and 7-9 species in Mexico. There are ten species in the genus Pyracantha with nine species recorded in China and one in Europe. Both Photinia and Pyracantha had a large morphological variation resulted in a great controversy on the division of the species. The extent collection will be made for the species of two genera, especially for the difficult species and complex populations. In this project, four main aspects will be discussed and resolved based on the methods and theory of micromorphology, palynology, cytology and molecular systematics. Firstly, revealing the taxonomic characters and its variability and accomplishing the classical taxonomic revision and the geographical distribution area revision; Secondly, discussing the differentiation and status of difficult species and complex populations by the micromorphological, palynological, cytological characters; thirdly, clarifying the status of the taxonomic taxa in Mexico; fourthly, improving the phylogeny research and determining the section, series and interspecific relationship among the species, then to establish a new classification system for the two genera.