亚洲叉蕨属（叉蕨科）的分类和系统学研究

The Tectaria is a pantropic fern genus comprising ca. 200 species, with its distribution center in the tropical Asia where ca. 150 species occur. In term of taxonomy, the modern revision of Tectaria is badly needed for most regions of Asia. For example in Indochina and neighbouring regions, the Tectaria has not been subjected to revision since 1940s. For a few countries or regions in Asia where modern floras are available, the treatment of Tectaria is generally unsatisfied as there are common confusions on the species’ identity. To date there is no an infrageneric classification of predictive value available for this group and thus the identification of species, as well as the grouping of species, is very difficult. Now we propose a project, the taxonomic revision and phylogenetic study of Tectaria from Asia, to address these problems. This project is an extension of our ongoing study, namely the taxonomic revision and phylogenetic study of Tectaria from East Asia. In the new project, we will take the conception of a monophyletic Tectaria and critically revised this group throughout Asia. The researches we would like to do include: 1) checking original materials of each species against its original publication to resolve the confusion of species names, 2) surveying and reevaluating characters which were used to set up species so as to clarify the true identity of dubious species, 3) reconstructing the phylogeny of Tectaria covering as many species as possible from Asia, and 4) combining data from morphology, molecular phylogeny, and phytogeography to group species, to interpret the divergence of species, and to discuss the origin, dispersal, and the current distribution pattern of each species of Tectaria in Asia. With the implement of this project we will critically revise the Tectaria of Asia as a whole for the first time and provide a case study to deal with a difficult, large genus based on morphological and molecular data. This project is of course significant in pushing the taxonomy of ferns in Asia and in understanding, as well as protecting, the biodiversity of tropical ferns.

叉蕨属以亚洲热带为现代分布中心，全球约200种，亚洲约150种。亚洲叉蕨属从未开展过专著性修订，各地叉蕨属的分类资料普遍陈旧，特别是中南半岛及邻近地区，70多年以来叉蕨属未经修订。部分地区虽然有较新近的植物志形式的修订，但是，叉蕨属下的名实不符和存疑种仍大量存在。叉蕨属至今没有一个有预见性的属下分类系统，种的鉴定与分群十分困难。针对这些问题，我们将在东亚叉蕨属分类和系统学研究的基础上，把研究区域扩展至整个亚洲，采用单系叉蕨属概念，全面梳理文献与标本，清理种的名实；进一步开展形态学资料调查与性状评价，阐明疑问种的真实身份；补充分子取样，构建完整的属下系统发育；比较形态性状在各分支之间的分化，解释亚洲叉蕨属的属下分群及种间关系，探讨亚洲各地叉蕨属植物的形态分化和地理分布规律。本项目将首次全面修订亚洲叉蕨属的分类，为解决热带蕨类大属的分类提供案例，促进蕨类植物分类学研究和热带蕨类植物多样性保护。

叉蕨属(Tectaria)以亚洲热带为分布中心，但亚洲叉蕨属一直缺乏全域性的分类研究，各地相关资料普遍陈旧，特别是中南半岛及邻近地区叉蕨属的资料自1940年以来没有更新。为了阐明亚洲叉蕨属的分类，我们开展了（1）亚洲及邻近区域叉蕨属全部种名的原始文献与模式标本的考证，（2）形态学性状的调查和分类学意义评价，（3）亚洲及邻近区域叉蕨属的分子系统发育重建和种间关系分析，以及（4）种的形态界定、地理分布修订及分布规律探讨。研究结果表明，（1）多变叉蕨等种类不是叉蕨属成员，应处理为一个不同的属（睡菜蕨属），而以T. lobbii为代表的流水植物确系叉蕨属成员，它们是T. angulata群的近亲；（2）Tectaria barberi–T. devexa演化支是叉蕨属中一个不可预知的旁系分支；（3）亚洲叉蕨属内存在4个复合群，即T devexa–simonsii群、T. fuscipes群、T. melanocaulis群和T. crenata–decurrens群，种间杂交导致了复合群内各物种的界限模糊；（4）亚洲（包含新几内亚）叉蕨属植物共有148种，其中东亚有38种，中南半岛有45种，南亚有31种，马来半岛有33种，婆罗洲有37种，印尼岛屿（不包括加里曼丹和西巴布亚）有37种，菲律宾有34种，新几内亚有34种；（5）亚洲及邻近的所罗门群岛有5个尚未描述的种，16个种应做归并处理；（6）叉蕨属在不同的地理区域内沿着多个不同的线路演化，亚洲的3个主要演化支和大多数次级演化支下都存在少数形态、地理或生境特化的种类；（7）叉蕨属在泛马来亚和亚洲大陆各有7个形态和DNA序列相关联的演化支，泛马来亚的种类主要沿着叶片简化并伴随叶脉充分连接、以及叶片细裂伴随叶脉分离的方向演化，而亚洲大陆的种类在各个方向上均有一定数量的代表，而沿着羽片呈篦齿状分裂并伴随叶脉分离或形成羽轴网眼、以及一回羽片全缘伴随叶脉网结方向演化的种类相对较多。本项目首次阐明了亚洲叉蕨属的物种多样性概貌、种间关系和种的地理分布，极大地推进了人们对这群植物的认识，为更深入探索这群植物的物种多样性形成和保护奠定了坚实基础。