瑞香属(Daphne L.)和荛花属(Wikstroemia Endl.)隶属于瑞香科(Thymelaeaceae)，在园林、造纸和药用方面都有广泛的应用。全世界共有瑞香属和荛花属植物160余种，中国有100余种。中国西南是两类群的重要分布中心。瑞香属和荛花属间的系统关系一直存在争议，两属植物内部的系统发育关系仍不清楚。本项目旨在以瑞香属和荛花属为主要研究对象，全面采集两属的植物种类，结合形态性状和基于叶绿体DNA与单拷贝或低拷贝的核基因序列的分子证据，对瑞香属、荛花属及邻近属进行系统发育重建。本研究将明确两分类群的系统分类地位、分类界限及相互间的亲缘关系，完成对已有属下分类等级的检验与修正，厘清近缘种、近似种及部分分类困难类群的分类地位。通过结合形态变异与分子证据探讨瑞香属与荛花属植物系统发育过程中的性状特征演化，进而为全面、合理地对瑞香属、荛花属进行分类修订提供重要的科学证据。

The genera Daphne L. and Wikstroemia Endl. belong to the family Thymelaeaceae with species widely used in horticulture, paper-making and medicine. The two genera included about 160 species worldwide in total, with 100 species distributing in China. South-western China is the important distribution center of both genera. The phylogenetic relationship between Daphne and Wikstroemia have been controversial for a long time and the infrageneric classification within each genus is still unclear. In this project, morphological characters，molecular sequences of single or low copy nuclear genes and chloroplast DNA sequences will be used to reconstruct the phylogenetic relationship among Daphne, Wikstroemia and other related genera based on comprehensive material collection. Consequently, the taxonomic status, generic limit as well the phylogenetic relationship of Daphne and Wikstroemia will be clarified. The intrageneric taxonomic structure within Daphne and Wikstroemia will be tested and revised. Meanwhile, the taxonomic status and species boundaries of some sibling species, morphologically similar species and several difficult to identify species will be confirmed. Furthermore, character evolution based on combination of morphological variation and molecular data will be traced to provide evidence for comprehensive and reasonable taxonomic revision of Daphne and Wikstroemia.