生物多样性 ›› 2018, Vol. 26 ›› Issue (3): 295-303.DOI: 10.17520/biods.2017219

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榕-传粉榕小蜂非一对一共生关系的研究进展

黄建峰1#, 徐睿2#, 彭艳琼1,*()   

  1. 1 中国科学院热带森林生态学重点实验室, 中国科学院西双版纳热带植物园, 云南勐腊 666303
    2 云南省热带作物科学研究所, 云南景洪 666100
  • 收稿日期:2017-09-16 接受日期:2018-03-27 出版日期:2018-03-20 发布日期:2018-05-05
  • 通讯作者: 彭艳琼
  • 作者简介:

    # 共同第一作者

  • 基金资助:
    国家自然科学基金(31672373)

Progress on the breakdown of one-to-one rule in symbiosis of figs and their pollinating wasps

Jianfeng Huang1#, Rui Xu2#, Yanqiong Peng1,*()   

  1. 1 Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303
    2 Yunnan Institute of Tropical Crops, Jinghong, Yunnan 666100
  • Received:2017-09-16 Accepted:2018-03-27 Online:2018-03-20 Published:2018-05-05
  • Contact: Peng Yanqiong
  • About author:

    # Co-first authors

摘要:

榕-传粉榕小蜂系统是研究动植物专性互惠共生关系的经典体系。早期形态学研究认为它们之间遵循一对一原则, 即1种榕树只有1种榕小蜂为其传粉, 而1种传粉榕小蜂也只能在1种榕树上繁殖后代。然而随着研究的深入, 报道了越来越多非一对一共生关系的案例, 尤其是隐存种的发现, 打破了一对一原则在榕-传粉榕小蜂系统中的普适性。非一对一共生关系包括多种传粉者共现于1种宿主榕树和多种榕树共享1种传粉者两种情况, 有各自不同的发生机制和规律。本文从形态学描述阶段、多学科综合证据阶段和传粉榕小蜂隐存种的发现3个阶段综述了榕-传粉榕小蜂非一对一共生关系的研究进展, 并对其所引发的科学问题进行了探讨。多种传粉者共现于1种宿主榕树的情况, 使得榕小蜂的种间杂交成为可能; 而多种榕树共享1种传粉者, 为宿主榕树的种间杂交提供了机会。然而, 杂交事件的检出率却很低, 暗示存在明显的生殖隔离。另外, 传粉者共现和共享传粉者两种情况在不同性系统榕树上的发生率和发生机制存在明显差异, 暗示不同性系统榕树的宿主专一性不同。大量小蜂隐存种的发现, 引发了对其成种机制、共现机制的研究, 以及对小蜂生物多样性的重新评估, 并给人工控制实验的开展带来了新的问题。每个榕-传粉榕小蜂组合都具有其独特的协同进化历史, 为研究动植物间的协同进化机制和规律提供了丰富素材。对榕-传粉榕小蜂专性互惠共生关系的形成、维持和打破机制开展综合研究, 才能充分认识该系统, 也有助于认识动植物间的协同进化过程和规律。

关键词: 榕树, 传粉榕小蜂, 一对一原则, 隐存种, 传粉者共现, 共享传粉者

Abstract:

The fig-fig-pollinating wasp symbiosis provides a model system for investigating the mutualistic interaction between plants and animals. A simple one-to-one rule was proposed to describe the highly specialized reciprocal relationships between figs and their species-specific pollinating fig wasps based on the initial studies: each fig tree species is obligatorily pollinated by one fig wasp species, and each wasp species can only reproduce in one fig species. With the deepening of research, however, increasing cases of breakdown in species-specificity have been reported, especially the reveal of cryptic pollinating fig wasp species progressively weaken the universality of one-to-one rule in fig-fig-pollinating wasp symbiosis. The documented cases of breakdown in the one-to-one rule were divided into two types, including copollinator and pollinator sharing, which have their own different mechanisms. Pollinator sharing is pollination of different species of Ficus by the same pollinator, while copollinator is the co-occurrence of more than one species of pollinators in one host fig. Here, the research progress on the breakdown of one-to-one rule is presented in three stages, i.e. morphological description, multidisciplinary evidence and discovery of cryptic pollinating wasp species. Some future challenges and research prospects resulted from the breakdown of one-to-one rule are outlined. Copollinators may lead to the interspecific hybridization between pollinator species, while pollinator sharing may result in the hybridization of host figs. Nonetheless, the hybridization in fig-fig-pollinating wasp symbiosis is very rare and suggests a strong level of reproductive isolation. Furthermore, the incidence and pattern of pollinator sharing and copollinator are differentiated in dioecious and monoecious figs, which suggests a differentiated host-specificity. The identification of cryptic species triggers the research of its speciation and co-occurrence, as well as the reassessment of pollinator biodiversity. Failing to recognize cryptic species also will limits the effectiveness of the controlled experiment in fig-fig-pollinating wasp symbosis. Each pair of fig and pollinating wasp possesses its distinctive coevolutionary history, and there are more than 750 pairs across the globe, which provide rich materials to explore the coevolutionary process and mechanism between plants and animals. The integrated study of formation, maintenance and breakdown mechanisms of the host-specificity will contribute to the understanding of fig-fig-pollinating wasp mutualism, and the coevolutionary process and mechanism between plants and animals.

Key words: fig, fig pollinating wasp, one-to-one rule, cryptic species, copollinator, pollinator sharing