缅甸北部杜鹃花科树萝卜属的分类学研究

Agapetes D. Don ex G. Don comprises approximately 100 currently recognized species, most of which are distributed in the Asian subtropical monsoon region. Northern Myanmar has a high diversity of Agapetes species. This genus not only contains ornamentally important taxa, with enlarged and swollen rootstocks and, in most species, beautiful and delicate flowers, but also forms an important component of the evergreen broad-leaved forest, mainly as epiphytes but occasionally terrestrial. In the northern part of Myanmar, limited specimen collections have resulted in an incomplete understanding of the variation of morphological traits. Combined with the lack of systematic study of scientific names and both type and non-type specimens of Agapetes, species delimitation within the genus is extremely difficult and obscure, and confusion exists in the identification of species within Agapetes, and with some of the epiphytic Vaccinium species. This study intends to continue conducting field investigations and collections in northern Myanmar and adjacent areas in China on the basis of previous taxonomic studies on Agapetes, based on specimen observations, with a combination of molecular methods as well as studies of the geographical distribution. We hope to evaluate different morphological characters and clarify the ambiguous and confusable species, to solve the existing taxonomic questions, to establish a new subgeneric classification system, and finally complete the taxonomic revision of Agapetes in northern Myanmar. This study will provide a basis for rational use of plant resources and shed light on the phylogeny of the tribe Vaccinieae.

杜鹃花科树萝卜属（Agapetes）全世界约有100种，广布亚洲亚热带季风区，该属植物种类在缅甸北部尤为丰富，是树萝卜属研究的关键区域。该属植物花型秀丽雅致，以附生为主，是常绿阔叶林重要标志物种，具有重要观赏和学术价值。由于标本采集不全，标本数量有限，对形态性状变异幅度认识不足，学名、模式和标本缺乏系统整理研究，树萝卜属还存在大量种级水平和部分属级水平的分类问题。本研究拟在前期对缅甸树萝卜属研究的基础上，继续对缅甸北部区域进行野外考察和采集，并对我国与缅甸北部邻近地区进行调查和补充采集，通过查阅世界各主要标本馆的馆藏标本，结合分子辅助鉴定和地理分布方面的研究，对树萝卜属植物形态性状变异进行细致研究，分析评价其分类学意义，厘清困难种类的划分，建立新的属下分类系统，完成属的分类修订。并为进一步澄清和解决该属与越橘属中附生类群的关系研究准备材料，同时本研究能为本属植物资源的合理开发利用提供依据。

在前期对缅甸树萝卜属采集积累的基础上，通过文献考证、模式标本研究，在国内中缅边境地区开展的多次野外采集，结合对我们前期引种的缅甸树萝卜属活植物相关种类的观察，并与国内外同行合作，对缅甸的树萝卜属植物进行了全面的梳理，主要结果有：(1) 发表了1个缅甸树萝卜属新种少齿树萝卜(Agapetes oligodonta Y. H. Tong, K. Armstr. & Bin Yang)，补充描述了尖叶树萝卜(A. epacridea Airy Shaw) 的花形态特征，并将A. odontocera var. stenosepala Airy Shaw 提升为种A. stenosepala (Airy Shaw) Y. H. Tong, Bin Yang & K. Armstr.，更新了一份具有标本引证的缅甸树萝卜属植物名录，包含56种，9变种，1变型。(2) 提供了缅甸树萝卜属近40种的彩色图版或精细线描图，为图志的编研奠定了坚实基础；(3) 发表了中国树萝卜属1个新种素华树萝卜 (A. huangiana Bin Yang, Y.H.Tan, Y.H.Tong)，2个新记录种腺苞树萝卜 (A. nana (Griff.) Hook.f.) 和葡萄树萝卜 (A. putaoensis Y.H. Tong & N.H. Xia)，补充了茶叶树萝卜 (A. camelliifolia S.H.Huang) 的花形态特征描述，并将光果树萝卜(A. leiocarpa S.H. Huang) 处理为钻萼树萝卜(A. atrosanguinea Airy Shaw) 的异名。基于我们对树萝卜属和越橘属附生类群的系统发育初步研究发现，树萝卜属与越橘属附生类群的系统发育关系比较复杂，缅甸和国产的附生越橘基本全部嵌套在树萝卜属内，它们是否应该全部归入树萝卜属还有待进一步深入研究，全面的分类修订还需要进一步开展广泛的国内外合作研究才能解决，因此本研究暂时没有对属下建立分类系统，但本项目为进一步澄清和解决树萝卜属与越橘属中附生类群的系统发育关系奠定了坚实的基础。