琼楠亚族隶属樟科厚壳桂族，是一个单系分支，泛热带分布，包含琼楠属、土楠属、油果樟属、孔药楠属、Potameia、Hexapora和Yasunia等7属。琼楠亚族内的属间关系混乱，主要问题包括：（1）该亚族内包含多少个属级分支？（2）如何用形态特征来定义亚族内的属？（3）属间关系如何？本项目拟采取如下方案：（1）完成物种编目，考察和分析形态特征，为取样、系统发育和定义分支等奠定基础；（2）分子系统学研究建立系统发育骨架；（3）联合形态和分子数据建立系统发育树，界定琼楠属群包含的属级分支，并确定属间关系；（4）开展特征分析，用共衍征定义属；（5）基于植物分类学原理和命名法规进行分类处理。琼楠亚族包含种类较多，包含很多经济利用价值高和受威胁严重的物种。本项目解决琼楠亚族的分类学问题对于完成全球樟科物种编目以及琼楠亚族物种资源利用和濒危物种保育有重要意义。

The Lauraceae are economically important as sources of medicine (e.g. Cinnamomum cassia and Lindera aggregata), timber (e.g., Phoebe spp.), nutritious fruits (e.g., Persea americana), spices (e.g., Cinnamomum cassia, C. subavenium, Laurus nobilis), camphor and essential oil of C. camphora used for making perfumes and medicines. However, many species remain poorly known and difficult to identify, some are even equivocal for their generic ascription. Modern plant taxonomy is based on phylogeny and monophyly is an essential prerequisite. The subtribe Beilschmiediineae Kosterm. belongs to the Tribe Cryptocaryeae of the Lauraceae, the subtribe is monophyletic and widely distributed in the pantropical region, it contains seven genera including Beilschmiedia, Endiandra, Syndiclis, Sinopora, Potameia, Hexapora, and Yasunia. Previous studies have suggested that a few genera in the subtribe are not monophyletic, and generic delimitation and relationships among the genera are ambiguous. The existing problems are: (1) due to inadequate sampling and low resolution of molecular markers in previous studies, it remains unclear how many generic clades are there in the subtribe? The subtribe has ca. 390 species in the world, 64 species were sampled in a recently published phylogeny, sampling from the Asia is extremely poor in the latest phylogeny; (2) it is unclear how to define the generic clades using morphological characters? (3) phylogenetic relationships among the known clades are poorly resolved based on ITS or trnK alone or combined. To tackle these taxonomic problems, we plan to: (1) catalog species of the subtribe based on field collections, herbarium specimens, and literature data, investigate morphological characters, which lay foundations for reasonable sampling, phylogeny and defining clades; (2) sample more Asian species, obtain more useful sequences, e.g. the low-copy nuclear LEAFY and RPB2, and the chloroplast psbA-trnH, rpl16, and trnL-F, then conduct molecular systematic studies to establish a backbone for a species-rich phylogeny; (3) reconstruct a phylogenetic tree based on a combined dataset including morphological and molecular data, delimit the generic clades and resolve phylogenetic relationships of the generic clades; (4) analyze morphological characters using Mesquite to define generic clades using morphological characters based on a new character analysis; (5) accomplish a new taxonomic treatment according to the latest nomenclatural code (will be the Shenzhen Code after 2017). The subtribe is speciose, and contains many economically important species and endangered species with confined distribution. A new taxonomy of the subtribe is of great significance in a world species catalogue of Lauraceae, resource utilization of species, and conservation of endangered species.