Asymmetrical nature of the Trollius–Chiastocheta interaction: insights into the evolution of nursery pollination systems

Ecology and Evolution

Tomasz Suchan¹  Mélanie Beauverd¹  Naïké Trim¹ 

[1] Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland

关键词: Asymmetrical interactions;    brood‐site pollination;    Chiastocheta;    conditional outcomes;    mutualism;    plant–pollinator interactions;    pollinator community;    pollinator loss;    reproductive ecology;    reproductive success;    Trollius europaeus;   

DOI  :  10.1002/ece3.1544

来源: Wiley

【 摘 要 】

Abstract

The mutualistic versus antagonistic nature of an interaction is defined by costs and benefits of each partner, which may vary depending on the environment. Contrasting with this dynamic view, several pollination interactions are considered as strictly obligate and mutualistic. Here, we focus on the interaction between Trollius europaeus and Chiastocheta flies, considered as a specialized and obligate nursery pollination system – the flies are thought to be exclusive pollinators of the plant and their larvae develop only in T. europaeus fruits. In this system, features such as the globelike flower shape are claimed to have evolved in a coevolutionary context. We examine the specificity of this pollination system and measure traits related to offspring fitness in isolated T. europaeus populations, in some of which Chiastocheta flies have gone extinct. We hypothesize that if this interaction is specific and obligate, the plant should experience dramatic drop in its relative fitness in the absence of Chiastocheta. Contrasting with this hypothesis, T. europaeus populations without flies demonstrate a similar relative fitness to those with the flies present, contradicting the putative obligatory nature of this pollination system. It also agrees with our observation that many other insects also visit and carry pollen among T. europaeus flowers. We propose that the interaction could have evolved through maximization of by-product benefits of the Chiastocheta visits, through the male flower function, and selection on floral traits by the most effective pollinator. We argue this mechanism is also central in the evolution of other nursery pollination systems.

【 授权许可】

CC BY   
© 2015 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.

Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.