有花植物与传粉动物之间的协同进化关系一直是进化生物学研究的核心问题。花部信号被传粉者接收后产生相应的传粉行为特征等方面已有丰富的理论和实证研究。但有关传粉者神经系统接收和处理花部信号的机制研究却很少，严重妨碍了对花部信号与传粉者之间协同进化关系的深入探讨。本项目拟以3种兰科植物的果蝇传粉系统，特别是无苞杓兰聚集性激素/性激素和食源性化合物混合花气味吸引传粉者的新机制为平台，借助模式生物黑腹果蝇的优势，率先开展导致果蝇传粉者行为的花气味化合物在果蝇大脑神经系统中被接收和处理的途径和机制等方面研究，探讨花气味信号与传粉昆虫初级嗅觉感受神经回路之间的进化适应关系，深入阐明花气味化合物成分与传粉者行为之间的关系。同时，利用模式生物黑腹果蝇解析传粉者在传粉活动中的行为特性和神经系统运行式样和机制的结果将为提高传粉者传粉效率贡献基础性理论和知识，为解决全球性的生态系统与农业系统传粉者不足‘添砖加瓦’。

Co-evolution of flowering plants and pollinators has been a core issue in evolution biology research. Numerous cases of the pollinating behavior characteristics evoked by floral volatile signals have been extensively studied. However, how the nervous systems of pollinators receive and transduce the floral volatile signals in pollination process is poorly understood. This situation hinders our deeply understanding of the evolution patterns between pollinator behaviors and floral volatile signals. Previous study reported that some orchids are pollinated by Drosophila species in reward or rewardless pollination systems, including Cypripedium bardolphianum, C. micranthum, Bulbophyllum penicillium, Specklinia endotrachys and related species. Our previous study found out a putative new floral volatile compounds attractive mechanism in C. bardolphianum. In this pollination system, the Drosophila pollinators are attracted by the floral volatile compounds as both sexual and food cues. The aims of this project are: 1) to analyze and bio-assess the effects of the main volatile compounds emitted by those orchid flowers; 2) to find out the specific glomerulus in the antennal lobe responding to the orchid floral volatile signals, and to address the primary neural mechanism processing the orchid floral volatile compounds in Drosophila melanogaster; 3) to identify the neural circuits activated by the floral volatile signals of those orchids in Drosophila pollinators, referring to their neural circuits counterpart in D. melanogaster. And our study will particularly focus on the floral volatile signals valued as sexual and food cues. Based on these neural circuits, we will explore the potential evolutionary adaptation mechanisms of floral volatile compounds and olfactory receptor neural circuits of Drosophila pollinators, especially the interaction between floral volatile compounds and pollinating behavior. The study of this interaction will deliver new insights into the pollinating behavior characteristics and neural mechanisms of pollinators in Orchid- Drosophila pollination system. Taken together the improvement of these basic theory and knowledge of pollination biology from our study can be considered as a new strategy to increase the pollinator efficiency, and eventually helps to buffer the global insufficiency of pollination services in ecosystems and agricultural systems.