比较钝叶榕的三种传粉者及其传粉效率

钝叶榕 (Ficus curtipes)是雌雄同株,它除了依赖钝叶榕传粉榕小蜂Eupristina sp.传粉外,另外两种进入果内繁殖的杨氏榕树金小蜂Diaziella yangi 和Lipothymus sp.金小蜂也能有效地为它传粉,这3种小蜂同时产卵于雌花的子房内,在榕果内繁殖后代.通过控制性放蜂试验,比较研究钝叶榕3种传粉者的传粉效率,结果表明:自然状态下,3种小蜂在绝大多数榕果里只各进1头.在控制性放蜂试验中,3种小蜂的传粉效率均随着放入雌蜂数量的增加而增加,两种金小蜂的传粉效率有时比钝叶榕传粉榕小蜂的传粉效率还高.当钝叶榕传粉榕小蜂分别与两种金小蜂同时放入榕果内传粉时,其生产的种子数量居于或者是接近两种小蜂单独传粉时形成的种子数量,传粉效率没有显著增加.在比较3种小蜂单种分别放1头和2头的传粉效率时,增加单果放蜂数量,钝叶榕传粉榕小蜂和Lipothymus sp. 的平均传粉效率降低,但杨氏榕树金小蜂的平均传粉效率是增加的.对3种不同属传粉小蜂传粉效率的比较,可为研究榕-蜂互惠系统的互惠的起源提供依据.

The comparison of three fig wasp pollinators and their pollination efficiency on Ficus curtipes

Figs and fig-pollination wasps (Agaonidae) are highly coevolved mutualists that depend completely on each other for continued reproduction. A few non-agaonid wasps can enter figs to oviposit and effectively pollinate their fig hosts. However, there are few studies that compare the pollination efficiency of agaonid and non-agaonid wasps. In Xishuangbanna, Ficus curtipes is monoecious, and is typically pollinated by agaonid Eupristina sp. Two species of non-agaonid wasps Diaziella yangi and Lipothymus sp. also enter the fig to oviposit and can effect pollination. These wasps are specific and strictly dependent on the fig for their development. The pollination efficiencies of the three species of fig wasps were compared in this study. We collected the data from natural populations and combined these with introduction experiments of the three species of fig wasps. We compared the contribution of three fig wasps to the seed production of F. curtipes. The results showed that the number of three fig wasps trapped in the fig cavity was usually one. However, as the number of conspecific foundresses per fruit increased, the number of seeds produced increased. Sometimes the pollination efficiency of D. yangi and Lipothymus sp. was even higher than that of Eupristina sp. When one Eupristina sp. and one non-agaonid wasp were introduced to enter a fig at the same time, the seed production did not significantly increase and the number of seeds was close to that when only one foundress of Eupristina sp. entered. This implied that D. yangi or Lipothymus sp. did not increase the pollination efficiency. When comparing the pollination efficiency of three fig wasps in one- and two-foundress broods, in two-foundress brood the average pollination efficiency of Eupristina sp. and Lipothymus sp. decreased, but that of D. yangi increased. The differences of pollination efficiency possibly result from different interactions between three fig wasps and the host Ficus. The results will be useful for further studying the mutualism origin of the fig-fig wasp interaction.