百合属的花进化和传粉生态学

To test hypotheses relevant to floral evolution, it is a fundermental method to combine phylogeny and pollination ecology. However,the flocal traits are still based on human cognitive abilities whereas the cognitive abilities of pollinators are significantly different from those of the humankind, which would inevitably lead to deviation in understanding of floral evolution and adaptation. For example, people are awkward to identify the ingredients of scents and nectar. In the present project, we focus on Lilium, which has the greatest diversity in China. This genus shows extroardinary floral diversity, indicating diverse pollination modes. With a well constructed phylogenetic tree, we address the following questions: 1) Are the repeated evolutionary transitions of floral syndromes inferred from the phylogenetic tree of Lilium associated with swithes in pollination modes? 2) Do the gredients of floral scents and nectar show divergence and/or parallelism in relation to evolutinary transitions of pollination systems? 3) Do the interspecific variation in composition of sugar and amino acid reflect the selection by pollinators?The project will broaden our understanding of how pollinators have driven the diversification of angiosperms. It will also lend support to the studies on the biogeographical history, speciation and coexsistence of Lilium. This genus has considerable ornamental and medical value. Pollination eological reference for conservation of the genus can be drawn from the results of our project.

将系统发育与传粉生态学相结合是验证与花进化有关的假说的重要方法。目前研究仍停留在基于人的认知的特征描述，而人与传粉者在认知上存在重大差异，这必然导致我们对花的进化和适应的理解偏差。该项目选取以我国为分布中心的百合属，此属花综合特征分化甚为明显，暗示多样化的传粉系统。我们以清晰的系统发育关系为前提，研究如下问题：1）百合属系统树上反映出的花部综合特征的多次进化转变是否与传粉模式的转变相关？2）花气味和花蜜成分的是否表现与传粉系统转变相关的歧化或趋同？3）花蜜氨基酸和糖成分的种间差异是否反映了传粉者的选择？该项目将拓宽对传粉者如何驱动被子植物多样化的理解，为探讨该属的演化史和物种形成及共存问题提供基础，且为这个具有重要观赏和药用价值的属的保护提供传粉生态学参考。