记者日前从中科院西双版纳热带植物园获悉，该园研究人员首次揭示了高榕上蜂等果这种新颖的榕树与榕小蜂协同进化机制，进而研究了榕小蜂延迟进果行为的进化生态学意义。相关成果发表于《科学公共图书馆·综合》。

据介绍，榕小蜂和榕树长期以来协同进化，但全球气候变化致使榕树和榕小蜂的生理协调不能很快适应，从而产生了蜂等果和果等蜂等特殊现象。

传粉榕小蜂的寿命非常短暂，一般只有1～2天。在自然界中，绝大部分榕小蜂会在找到合适的寄主榕树之前就死去，而很多榕树也会因为没有榕小蜂来访而遭受败育的命运。

“我们在西双版纳的高榕上，发现一种特殊的蜂等果现象：高榕的传粉小蜂和欺骗者小蜂会在榕树雌花期到来前数天，就大量来到叶片上等待，但此时的高榕果外还包着一层外壳，使提前到来的榕小蜂无法进入果内产卵和传粉。”博士生张媛说，研究显示经过等待行为的小蜂，后代数量和体型大小都下降，却能增加榕果种子数量，榕果的年龄也会影响榕—蜂的繁殖比例。（来源：中国科学报 张雯雯）

Premature Attraction of Pollinators to Inaccessible Figs of Ficus altissima:

A Search for Ecological and Evolutionary Consequences

Abstract  Adult life spans of only one or two days characterise life cycles of the fig wasps (Agaonidae) that pollinate fig trees (Ficus spp., Moraceae). Selection is expected to favour traits that maximise the value of the timing of encounters between such mutualistic partners, and fig wasps are usually only attracted to their hosts by species- and developmental-stage specific volatiles released from figs at the time when they are ready to be entered, oviposited in and pollinated. We found that Ficus altissima is exceptional, because it has persistent tight-fitting bud covers that prevent its Eupristina altissima pollinator (and a second species of ‘cheater’ agaonid) from entering its figs for several days after they start to be attracted. We examined the consequences of delayed entry for the figs and fig wasps and tested whether delayed entry has been selected to increase adult longevity. We found that older pollinators produced fewer and smaller offspring, but seed production was more efficient. Pollinator offspring ratios also varied depending on the age of figs they entered. The two agaonids from F. altissima lived slightly longer than six congeners associated with typical figs, but this was explainable by their larger body sizes. Delayed entry generates reproductive costs, especially for the pollinator. This opens an interesting perspective on the coevolution of figs and their pollinators and on the nature of mutualistic interactions in general.

原文链接：http://www.plosone.org/article/fetchObject.action?uri=

info%3Adoi%2F10.1371%2Fjournal.pone.0086735&representation=PDF