陆露博士，指导教师：李德铢研究员、王红研究员

学位论文题目：杜鹃花科白珠树族系统发育与生物地理学

学位论文摘要：

白珠树族（Gaultherieae）是杜鹃花科越桔亚科的一个单系群，包括6属约250种，呈典型环太平洋分布，主要分布在热带亚洲和热带美洲。该族内各属的系统位置和属间、属下关系一直倍受争议。本研究基于孢粉学和种子形态学的实验手段，研究了白珠树族相关形态特征的演化过程和系统学意义，为进一步对该族的分类学修订提供重要形态性状。研究结果发现，白珠树族相关类群花粉的沟间区纹饰的演化趋势是由颗粒状通过颗粒－皱纹状至皱纹状，这种趋势不限于越桔亚科。花粉和种子形态均与地理分布有关。种子形态多样化可能是对不同种子散布方式的适应，一些特化的种子结构具有特殊的生态功能。同时，利用ITS、rpl16、trnL-F、trnG-S和matK等基因片段，分别重建白珠树族及族下的“中国—喜马拉雅分支”的系统发育。探讨了族下各分支的系统关系，也对“中国—喜马拉雅分支”内可能存在的网状进化进行了分析。最后，结合前人的工作，对白珠树族地理分布样式成因和可能的起源地进行了初步探讨。结果表明白珠树族可能起源于温带北美洲，这为杜鹃花科及其科下阶元起源地的“boreotropics”假设提供了有利的证据。温带南美洲是大洋洲类群（新西兰、澳大利亚和塔斯马尼亚）的起源地。长距离扩散和隔离分化在白珠树族的演化中也可能发挥了重要作用。

The tribe Gaultherieae, consisting of six genera (ca. 250 species), forms a monophyletic group within subfamily Vaccinioideae of the Ericaceae. It exhibits a distinctive amphi-Pacific distribution and the bulk of the distribution is tropical and subtropical. The intergeneric and infrageneric relationships of Gaultherieae based on morphological study have been debated for a long time. In this dissertation, palynology and seed morphology of Gaultherieae were studied for employing more critical characters (synapomorphies) for the reclassification. It seems that an evolutionary trend of mesocolpium ornamentation within Vaccinioideae from granulate through granulate–rugulate to rugulate is apparent, and the pattern is not limited to Vaccinium per se. Both pollen and seed morphology have geographic significance. Seed variety can be inferred to be significant for adapting to different dispersal ways. Some special structures of seed may involve in ecological functions. The phylogeny of Gaultherieae and the Sino-Himalayan Clade were reconstructed based on the related molecular data (ITS, rpl16, trnL-F, trnG-S and matK) with intensive sampling. Systematic relationships within Gaultherieae and the possible reticulate evolution within the Sino-Himalayan Clade were discussed. Based on the previous work, origins and biogeographic patterns in Gaultherieae were preliminarily discussed. A North American origin was assigned to the base of the Gaultherieae. It positively supports the boreotropics hypothesis for the origin of the Ericaceae. The Oceanian taxa (New Zealand, Australia and Tasmania) may be derived from the temperate South American ancestors.Long-distance dispersal and vicariance may facilitate evolution of the tribe Gaultherieae.