多花兰传粉生物学研究

Pollination biology of Cymbidium floribundum(Orchidaceae)

传粉是植物繁殖和进化的一个关键环节,为探讨中国产多花兰(Cymbidium floribundum)的传粉生物学特性,对其开花物候、繁育系统、花的挥发性成分、传粉昆虫行为学实验进行了研究。结果表明,多花兰不存在自动自交和无融合生殖,种子的形成有赖于传粉媒介。其自然结实率远低于人工授粉,存在严重的传粉限制。中华蜜蜂(Apis cerana)为多花兰的有效传粉昆虫,但未能从中获得报酬,在传粉过程中将花粉块连药帽一起带出。通过昆虫的行为学实验发现,多花兰气味对中华蜜蜂具有显著性吸引作用,而颜色对中华蜜蜂无显著性吸引作用。花朵的主要挥发性成分为醛类与醇类物质,一天之中在种类和量上几乎没有变化,只有芳樟醇含量的变化与传粉昆虫活动频率相关。本研究可为兰多花兰的野生保护和杂交育种提供一定依据。

Pollination is a key link in plant reproduction and evolution.In order to explore the pollination biological characteristics of Cymbidium floribundum,the flowering phenology,breeding system,flower volatile components and behavior of pollinating insects were studied.The results showed that there was no automatic selfing and apomictic reproduction in C.floribundum,and the formation of seeds depended on pollinators.Its natural seed setting rate was much lower than that of artificial pollination,and there were serious pollination restrictions.Apis cerana was an effective pollinator for C.floribundum,but it could not get reward from the plants.During pollination,the pollinium was taken out together with the cap.Through the behavioral experiments of insects,it was found that the odor of C.floribundum played a key role in attracting pollinators,while the color had no significant attractive effect on A.cerana.The main volatile components of flowers were aldehydes and alcohols,and there was almost no change in type and amount in a day for the volatile components.Only the change in linalool content was related to the frequency of pollinating insects.This study could provide a certain basis for wild protection and hybrid breeding of orchids.