Friedman Jannice, Barrett Spencer C H
Department of Ecology and Evolutionary Biology, University of Toronto, Ontario, Canada.
Ann Bot. 2009 Jun;103(9):1515-27. doi: 10.1093/aob/mcp035. Epub 2009 Feb 14.
The rich literature that characterizes the field of pollination biology has focused largely on animal-pollinated plants. At least 10 % of angiosperms are wind pollinated, and this mode of pollination has evolved on multiple occasions among unrelated lineages, and hence this discrepancy in research interest is surprising. Here, the evolution and functional ecology of pollination and mating in wind-pollinated plants are discussed, a theoretical framework for modelling the selection of wind pollination is outlined, and pollen capture and the occurrence of pollen limitation in diverse wind-pollinated herbs are investigated experimentally.
Wind pollination may commonly evolve to provide reproductive assurance when pollinators are scarce. Evidence is presented that pollen limitation in wind-pollinated plants may not be as common as it is in animal-pollinated species. The studies of pollen capture in wind-pollinated herbs demonstrate that pollen transfer efficiency is not substantially lower than in animal-pollinated plants as is often assumed. These findings challenge the explanation that the evolution of few ovules in wind-pollinated flowers is associated with low pollen loads. Floral and inflorescence architecture is crucial to pollination and mating because of the aerodynamics of wind pollination. Evidence is provided for the importance of plant height, floral position, and stamen and stigma characteristics in promoting effective pollen dispersal and capture. Finally, it is proposed that geitonogamous selfing may alleviate pollen limitation in many wind-pollinated plants with unisexual flowers.
描述传粉生物学领域的丰富文献主要集中在动物传粉植物上。至少10%的被子植物是风媒传粉的，并且这种传粉方式在不相关的谱系中已经多次进化，因此这种研究兴趣上的差异令人惊讶。在此，讨论了风媒传粉植物传粉和交配的进化及功能生态学，概述了一个用于模拟风媒传粉选择的理论框架，并通过实验研究了多种风媒传粉草本植物的花粉捕获情况以及花粉限制的发生情况。
当传粉者稀缺时，风媒传粉可能通常会进化以提供繁殖保障。有证据表明，风媒传粉植物中的花粉限制可能不像动物传粉物种中那样常见。对风媒传粉草本植物花粉捕获的研究表明，花粉转移效率并不像通常所认为的那样比动物传粉植物低很多。这些发现对风媒传粉花中胚珠数量少的进化与低花粉载量相关这一解释提出了挑战。由于风媒传粉的空气动力学特性，花和花序结构对传粉和交配至关重要。有证据表明，株高、花的位置以及雄蕊和柱头特征在促进有效花粉传播和捕获方面具有重要性。最后，有人提出，在许多具有单性花的风媒传粉植物中，同株异花授粉的自交可能会减轻花粉限制。
