Differences in floral morphology are often hypothesized to stem from selection by different pollinators. Thus, the presence of multiple floral color morphs within a species might indicate visitation by different pollinator species. To test this prediction, we examined Ipomoea aquatica Forssk., a morning glory species with a “white” morph (all-white flowers) and a “purple” morph (white corolla lobes with purple corolla tubes). We studied this species in Nong Khai, Thailand, where some populations are monomorphic for a single color and others are polymorphic. We compared (a) animal visitation rates to each morph; (b) visitor and pollinator community composition at each morph; and (c) the female reproduction of each morph. Visitation rates were obtained from camcorder footage and used to analyze community composition. Female reproduction was assessed from a pollination experiment with five treatments (open, open emasculation, hand-cross, hand-self, and closed). We found that the main pollinators (bees and butterflies) visited both morphs, and that overall insect community composition to the two floral colors did not differ significantly. Moreover, we found that I. aquatica is capable of spontaneous autogamy but still benefits from pollinators, as flowers in the closed treatment set significantly fewer seeds than flowers in the open and hand cross-pollinated treatments. When comparing female reproduction between morphs, we did not find significant differences for either fruit set or seed set. These findings suggest that floral visitors interact with the two morphs similarly, and that the high-reproductive success experienced by both colors may help maintain the polymorphism in nature.

中文翻译：

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Ipomoea Aquatica (Convolvulaceae) 两种花色变体的传粉者访问和雌性繁殖成功

通常假设花形态的差异源于不同传粉者的选择。因此，一个物种内存在多种花色变形可能表明不同传粉媒介物种的造访。为了测试这一预测，我们检查了 Ipomoea Aquatica Forssk.，一种具有“白色”变体（全白花）和“紫色”变体（带有紫色花冠管的白色花冠裂片）的牵牛花物种。我们在泰国廊开研究了这个物种，那里的一些种群是单一颜色的单态，而其他种群是多态的。我们比较了（a）每个变种的动物访问率；(b) 每个形态的访客和传粉媒介群落组成；(c) 每个变种的雌性繁殖。访问率是从摄像机镜头中获得的，并用于分析社区组成。雌性繁殖是根据具有五种处理（开放、开放去雄、手交、手自和和闭合）的授粉实验评估的。我们发现主要传粉者（蜜蜂和蝴蝶）访问了两种变体，并且两种花色的整体昆虫群落组成没有显着差异。此外，我们发现 I.aquatica 能够自发自交，但仍然受益于传粉媒介，因为在封闭处理中的花比在开放和手工异花授粉处理中的花结出的种子少得多。在比较不同变体之间的雌性繁殖时，我们没有发现坐果或结实的显着差异。这些发现表明，花卉访客与这两种变体的互动方式相似，