东亚和东南亚地区唇鳞苔属分类学研究

The genus Cheilolejeunea is the third largest genus in Lejeuneaceae, consisting of approximately 80 to 100 species that widely distributed in the tropical and subtropical regions. East and Southeast Asia regions are one of the distribution centers of Cheilolejeunea, with 52 species recorded, which account for about half of the species within the genus. The circumscription of Cheilolejeunea has been re-delimitated by recent molecular phylogeny studies, in which the results support a broad concept of this genus. However, the genus has never been revised since established. This holds especially true for species in the East and Southeast Asia regions. Species diversity there is yet to be clarified, as well as the delimitations of species. With reference to the up-to-date backbones of Cheilolejeunea, the present program will provide morphological evidence for infrageneric classification on the basis of studies both on phylogeneric variation patterns and morphology of main charactistics of Cheilolejeunea in East and Southeast Asia. The taxonomic and nomenclature problems will be solved based on analyses of variation pattern of morphology of Cheilolejeunea through field investigation and examination of herbarium specimens. In combine with molecular evidence, the systematic position of difficult species will also be determined. Accordingly the true diversity of the genus will be confirmed. On this ground, the taxonomic revision of Cheilolejeunea in East and Southeast Asia will be accomplished. The present program will allow us to further understand the phylogeny of Cheilolejeunea and Lejeuneaceae. The knowledge of the diversity of Cheilolejeunea in East and Southeast Asia will lay foundations for a comprehensive knowledge of this genus worldwide, as well as the conservation of the genus.

唇鳞苔属是细鳞苔科的第三大属，包含80-100种，主要分布于热带和亚热带地区。东亚和东南亚地区是该属的分布中心之一（52种），物种数约占属内总种数的一半。近期的分子系统发育研究支持广义唇鳞苔属的处理，重新界定了属的范围。该属自从建立以来一直未被全面修订过，特别是东亚和东南亚地区，物种多样性尚未清晰，物种界限尚不明确。本项目将参考新的分子系统骨架，对东亚和东南亚的唇鳞苔属植物主要分类特征进行综合分析，讨论性状的变异规律，为建立属下分类系统提供形态学依据。通过标本研究和野外考察，研究唇鳞苔属植物形态的变异式样，解决分类上和命名上的问题，同时结合分子生物学证据，确定疑难种的系统位置。最终确认该属在东亚和东南亚地区的真实物种多样性，完成该区域唇鳞苔属的全面修订。项目的开展有助于对唇鳞苔属和细鳞苔科系统发育的进一步了解，并将为全面了解世界唇鳞苔属的物种多样性奠定基础，为多样性保护提供依据。

唇鳞苔属是细鳞苔科的第三大属，包含80-100种，主要分布于热带和亚热带地区。该属在东亚和东南亚地区分布的种类约占全属总种数的一半（现接受45种）。该属自从建立以来一直未被全面修订过，特别是东亚和东南亚地区，物种多样性尚未清晰，物种界限尚不明确。本项目对东亚和东南亚的唇鳞苔属植物主要分类特征进行综合分析，解决了属内几个遗留的分类学问题，并在系统发育的框架下，检测了形态分类特征划分类群的可靠性。主要结果如下：1）结合分子生物学证据和形态学的研究，确定了高氏唇鳞苔不属于唇鳞苔属，而应确立为新属：高氏苔属Gaolejeunea，高氏苔（Gaolejeunea gaoi）为我国特有的濒危苔藓植物；2）提出了两个新组合，Cheilolejeunea obtusistipula (Steph.) W.Ye和 C. papulifolia (Steph.) W.Ye；3）发现淡鳞苔属与唇鳞苔属存在名称优先权的冲突，提议保留唇鳞苔属的名称；4）根据分子实验初步结果结合形态学的证据，确认了研究区域内分布的C. insica、C. lindenbergii、C. parkinsonii和C. trifaria这四个形态上非常相近的种，存在着分子系统水平上的分化，传统的分类学依据例如腹叶分裂的程度、腹瓣上齿的形状和大小，依然对物种的界定具有重要的参考意义；5）发现了新加坡细鳞苔科的新种，Gaolejeunea hoi W.Ye & Y.M.Wei，进一步加深了对东南亚苔藓多样性的了解，为生物多样性的本底和物种保护提供了新的资料; 6）分析了海南苔藓植物多样性，及其与环境异质性的关系。结果表明，最优模型选择降水量为主要气候因子，显示了8个潜在的易危种特有种，并鉴别中央山地为苔藓的热点地区。环境异质性的关联研究表明现有的森林保护区对于当地的苔藓植物物种多样性至关重要。