Evolution of pollinator generalization in bumblebee-pollinated plants
Evolution of pollinator generalization in bumblebee-pollinated plants
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DOI：
10.1111/j.1442-1984.2007.00187.x
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发表时间：
2007-12-01
影响因子：
1.4
通讯作者：
Hiei, Kayako
中科院分区：
文献类型：
--
作者：
Suzuki, Kazuo;Dohzono, Ikumi;Hiei, Kayako
为了了解植物花部形态和繁殖策略之间的关系，需要研究多种传粉者对植物繁殖成功的贡献。为了概述这一主题的最新进展，我们回顾了日本的五种熊蜂授粉植物的研究。这些植物物种由一至三种不同喙长的熊蜂授粉：Bombus consobrinus，Bombus diversus和Bombus honshuensis。这些授粉系统使我们能够比较由单一和多个熊蜂物种授粉的植物的繁殖策略。首先，我们讨论了花和传粉者之间的形态对应对植物繁殖成功的影响。在具有窄管状花的植物中，阴花香茶菜和铁线莲的授粉效果取决于花管长度和传粉者口器之间的形态对应。这些花受到不同方向和强度的选择，由多个熊蜂物种，导致在维持大的变化，在花的形态内和种群之间，甚至在个人。与此相反，授粉有效性的植物有一个广泛的入口，Melampyrum roseum和玉簪，没有不同的熊蜂物种之间，因为花的形态和熊蜂的身体大小之间的良好的对应关系，导致花之间的小形态变化。因此，具有多个传粉者物种的广义传粉系统有利于能够使用各种传粉者的花性状。其次，我们解决熊蜂授粉植物授粉服务的数量和质量。阴花香茶菜传粉系统普遍，但授粉质量低，花粉受限。而具有特殊授粉系统的细花香茶菜，由于授粉量低而受到花粉限制。阴花香茶菜产生大量的短管状花以提高授粉量，而香茶菜则产生大量的短管状花。effusus产生少量的长管状花以提高授粉质量，导致植物内花的大小和数量之间的明显权衡。In M. roseum，其中有一个广义的授粉系统，三个熊蜂物种实现了充分的授粉，但种子生产受到限制的自花授粉率增加。这是因为该物种通过选择性败育自交种子而将更多资源投资于异花授粉种子。研究结果表明，广义植物的策略是提高授粉量，而特化植物的策略是提高授粉质量。
To understand the relationships between floral morphologies and the reproductive strategies of plants, the contributions of multiple pollinators to plant reproductive success need to be examined. To outline recent advances on this topic, we review studies of five bumblebee-pollinated plants in Japan. These plant species are pollinated by one to three bumblebee species differing in proboscis length: Bombus consobrinus, Bombus diversus and Bombus honshuensis. These pollination systems allow us to compare the reproductive strategies of plants pollinated by single and multiple bumblebee species. First, we address the effects of morphological correspondence between flowers and pollinators on the reproductive success of plants. In plants with narrow tubular flowers, Isodon umbrosus and Clematis stans, pollination effectiveness depended on the morphological correspondence between floral tube length and pollinator mouthparts. These flowers are subject to varied directions and intensities of selection by multiple bumblebee species, resulting in the maintenance of large variation in floral morphology within and between populations, and even within individuals. In contrast, pollination effectiveness in plants having flowers with a wide entrance, Melampyrum roseum and Hosta sieboldiana, did not differ among bumblebee species because of good correspondence between floral morphology and bumblebee body size, resulting in small morphological variations among flowers. Thus, generalized pollination systems with multiple pollinator species favor floral traits that enable the use of various pollinators. Second, we address the quantity and quality of the pollination service in bumblebee-pollinated plants. Isodon umbrosus, with its generalized pollination system, suffered from pollen limitation because of low pollination quality. In contrast, Isodon effusus, which has a specialized pollination system, suffered from pollen limitation because of low pollination quantity. Isodon umbrosus produced large numbers of short tubular flowers to improve pollination quantity, whereas I. effusus produced small numbers of long tubular flowers to improve pollination quality, resulting in a clear trade-off between the size and number of flowers within plants. In M. roseum, which has a generalized pollination system, three bumblebee species achieved sufficient pollination, but seed production was limited by an increased rate of self-pollination. This is because this species invests more resources in cross-pollinated seeds by selective abortion of selfed seeds. Our results demonstrate that the strategy of generalized plants is to improve pollination quantity, whereas the strategy of specialized plants is to improve pollination quality.