摘要
榕属植物及其传粉昆虫榕小蜂是自然界协同进化的经典模型,榕果内雌花资源如何分配一直是备受关注的问题。为验证季节变化对榕树榕小蜂互利共生系统生长与繁殖的影响,该研究以西双版纳地区的聚果榕(Ficus racemosa)为材料,分析了季节变化对榕果大小、自然进蜂量以及榕树榕小蜂繁殖的影响,并利用人工控制性放蜂实验和模型拟合,探讨榕果最适进蜂量及不同季节进蜂量对雌花资源分配的影响。结果表明:季节对榕果直径有显著影响,雨季的榕果直径显著小于干热季和雾凉季;不同季节的自然进蜂量也有显著差别,苞片口对调节进蜂数量有重要作用;季节对榕树榕小蜂繁殖分配也有影响,雾凉季产生的种子数量和榕小蜂数量均最多;同时人工控制实验和二次抛物线模型拟合结果表明,母代雌蜂数量与种子及榕小蜂后代数量均呈抛物线关系,雌蜂数量过多或过少都对榕树榕小蜂的繁殖不利,自然进蜂量与拟合的最优进蜂量基本一致。研究结果说明榕果进化出了适应西双版纳地区季节变化的繁殖策略。
The interaction between pollinating fig wasps （Agaonidae） and their host fig trees （Ficus） is a striking ex- ample of an obligate pollination mutualism. The reproductive allocation of female flowers resource in fig is attracting lasting interests of researchers. To verify how reproductive strategies of figs are affected by seasonal change, F. rece- mosa was used to analyze how the fig size, foundress numbers and reproductive resources allocation of fig-fig wasp change with seasons. We also conducted controlling introduction experiment on F. recernosa to explore how seed and fig offspring number change with foundresses number. Statistical model was used to fit the relationship between seed/wasp offspring number and foundresses number to estimate the optimal foundresses number, as well as the consequence of foundresses number in nature to fig-fig wasp reproduction. The results showed that fig size was signif- icantly influenced by season, figs in rainy season were smaller than figs in warm dry season and cold dry season. Sea-sonal change also had significant impact on foundress numbers in nature, and fig bract played an important role in blocking the redundant foundresses. Our results also showed that the reproduction of fig-fig wasp varied seasonally, the number of seed and wasp offspring reached the highest in cold dry season. The results of controlling introduction experiment and statistical model showed that the relationship between foundresses numbers and seed/wasp offspring number fitted quadratic parabola model, either excessive or too few foundress was unfavourable for fig-fig wasps re- production. The foundresses number in nature was approximately equal to optimal foundresses number. Our experi- mental results suggested that F. recemosa had evolved the reproductive strategies to adapt seasonal change in Xishuangbanna.
出处
《广西植物》
CAS
CSCD
北大核心
2015年第4期500-506,共7页
Guihaia
基金
国家自然科学基金(31100279)
云南省应用基础研究计划项目(2013FD023)
西南林业大学科研启动基金
关键词
雌雄同株
传粉榕小蜂
季节变化
繁殖对策
权衡
monoecy
pollinating fig wasps
seasonal change
reproductive strategy
trade-off
