Department of Neurobiology and Behavior, Seeley G. Mudd Hall, Cornell University, Ithaca, NY 14853, USA.
Ecol Lett. 2012 Dec;15(12):1362-9. doi: 10.1111/j.1461-0248.2012.01857.x. Epub 2012 Aug 27.
Host sanctions that reduce the relative fitness of uncooperative symbionts provide a mechanism that can limit cheating and thus stabilise mutualisms over evolutionary timescales. Sanctions have been demonstrated empirically in several mutualisms. However, if multiple individual symbionts interact with each host, the precision with which individual cheating symbionts are targeted by host sanctions is critical to their short- and long-term effectiveness. No previous empirical study has directly addressed this issue. Here, we report the precision of host sanctions in the mutualism between fig trees and their pollinating wasps. Using field experiments and molecular parentage analyses, we show that sanctions in Ficus nymphaeifolia act at the level of entire figs (syconia), not at the level of the individual flowers within. Such fig-level sanctions allow uncooperative wasps, which do not bring pollen, to avoid sanctions in figs to which other wasps bring pollen. We discuss the relevance of sanction precision to other mutualisms.
宿主制裁会降低不合作共生体的相对适合度，为限制欺骗行为提供了一种机制，从而在进化时间尺度上稳定互利共生关系。在几种互利共生关系中已经有实证研究证明了制裁的存在。然而，如果多个个体共生体与同一个宿主相互作用，那么宿主制裁针对个别欺骗共生体的精确性对于其短期和长期效果至关重要。以前没有任何实证研究直接解决这个问题。在这里，我们报告了在榕属植物与其传粉蜂之间的互利共生关系中，宿主制裁的精确性。通过野外实验和分子亲缘关系分析，我们表明，在榕属植物 Ficus nymphaeifolia 中，制裁作用于整个榕果（隐头花序），而不是单个花朵。这种针对榕果的制裁允许不携带花粉的不合作胡蜂避免因其他胡蜂携带花粉而受到制裁。我们讨论了制裁精确性对其他互利共生关系的相关性。
