榕树高度专性共生体系内影响传粉蜂子代繁殖的因素

Influence Factors on Offspring Reproduction of Pollinator in a Highly Species-specific Mutualism of Ficus

为探讨影响传粉蜂子代数量及性比的因素,以广州地区分布的粗叶榕(Ficus hirta Vahl)及其传粉小蜂爪哇榕小蜂(Valasia javana Mayr)为材料,采用自然收蜂与控制放蜂试验进行研究。结果表明,果内的榕小蜂群落随季节更替发生显著变化,非传粉蜂的介入、季节差异使雌蜂间的干扰强度不同,导致传粉蜂子代数量发生变化,其中雌蜂间的干扰会使传粉蜂性比显著升高,而非传粉蜂的介入对传粉蜂性比的影响不大,传粉蜂仍能正常地进行繁殖。另外,传粉蜂在雌花期雄花序内的产卵和存活时间一般较短,约为15 h;传粉蜂子代在干、湿季的雄花序内的发育时间差异显著,干季时间长,湿季时间短。这表明传粉榕小蜂进化出了适应广州地区季节变化的繁殖策略。

The interaction between pollinating fig wasps(Agaonidae)and their host fig trees(Ficus,Moraceae)is a striking example of an obligate pollination mutualism.The effect factors on number and sex ratio of offspring wasps were studied by using F.hirta Vahl-waps(Valasia javana Mayr)system.The results showed that the community of fig wasps offspring had significant changes in different seasons.The number of pollinator offspring changed caused by non-pollinating fig wasps and foundress interference derived from season.The foundress interference increased sex ratio of offspring fig wasps significantly,but non-pollinating fig wasps had no effect on sex ratio.In addition,the survival time of pollinating wasps at female phase was about15h and the development time of pollinating wasps had significant difference between dry and wet seasons,which was long in dry season and short in wet season.Therefore,it was suggested that the pollinators of Ficus hirta had evolved the reproductive strategies to adapt seasonal change in Guangzhou.