广义报春苣苔属(苦苣苔科)系统学研究

The Chinese monotypic genus Primulina has been recently enlarged to include Chirita sect.Gibbosaccus, Chiritopsis and Wentsaiboea in our present work.In the expanded genus,generic delimitation, intrageneric assignment,.character evolution and the position of some debated taxa will need to be addressed in subsequent work.This investigation will be carried out by combining molecular phylogeny and morphological considerations on SEM of pollen and seed,cytology and floral development in Primulina sensu lato and allies.We will assess the homology and diversity of these taxa and evolutionary and developmental patterns,find a better place for problematic species, present a systematic treatment of Primulina sensu lato as objective as possible, and test dated taxonomic classification. The survey on the core genus of Cyrtandroideae will not only be dealt with these chronically debated problems,but also form the solid foundation for phylogenetic reconstruction of the whole Gesneriaceae.

我们的前期工作将中国单种属报春苣苔属Primulina的概念进行了扩大，使其包括唇柱苣苔组Chirita sect. Gibbosaccus、小花苣苔属Chiritopsis和文采苣苔属Wentsaiboea。但扩大的报春苣苔属种的范围、属下分类系统、属内演化趋势以及疑难类群的系统位置等遗留问题亟待解决。本研究拟对广义报春苣苔属Primulina sensu lato及其近缘类群的花粉和种子显微结构、细胞学和花发育等形态特征进行观察，结合分子系统发育关系研究，分析相关类群的同源性和多样性以及其进化发育式样，澄清疑难种的分类地位，构建该属属下近乎自然的分类系统，并对前人分类系统进行验证或订正。该项目的完成不仅将解决该属长期以来所争议的问题，而且由于该属为苦苣苔亚科的核心类群，本项目的研究结果也将为整个苦苣苔科全面系统发育重建打下坚实的基础。

为了阐明广义报春苣苔属Primulina sensu lato及与相关类群系统发育关系，本研究首先基于核核糖体DNA内转录间隔区ITS、叶绿体DNA基因间隔区trnL-F和atpB-rbcL等3片段序列数据，运用最大简约法、最大似然法、贝叶斯推论法对广义报春苣苔属及其相关类群共138个分类群的单个及联合序列数据集进行了系统发生关系构建，并结合花粉、种表皮微结构和染色体数目等形态学数据，解决了一些疑难类群的系统位置问题，也界定了广义报春苣苔属的范围。. 结果表明广义报春苣苔属包括：1）小花苣苔属所有类群；2）文采苣苔属Wentsaiboea中两个种，即文采苣苔和罗城文采苣苔，而将天等文采苣苔Wentsaiboea tiandengensis移入到石山苣苔属Petrocodon中；3）唇柱苣苔属唇柱苣苔组Chirita sect. Gibbosaccus应该排除多痕唇柱苣苔亚组subsect. Cicatricosae，其中多痕唇柱苣苔C. minutihamata和弯果唇柱苣苔C. cyrtocarpa应该移入到奇柱苣苔属Deinostigma，滇川唇柱苣苔C. forrestii和康定唇柱苣苔C. tibetica应该并入汉克丽亚花属Henckelia。同时也支持了广义的石山苣苔属Petrocodon包括朱红苣苔属Calcareoboea和东南长蒴苣苔Didymocarpus hancei，与广义报春苣苔属为姐妹群关系。. 其次，以石山苣苔属Petrocodon为外类群，基于核基因ITS和4个叶绿体片段（rpL32-trnL,trnH-psbA,trnL-F,trnT-L），同样对报春苣苔属进行了系统发育重建。结果发现：报春苣苔属85个类群聚成三大分支和一个小分支，有待于进一步进行属下分类。该项目的完成不仅解决该属长期以来所争议的问题，而且为整个苦苣苔科全面系统发育重建打下了坚实的基础。