Abstract：
Hybridization is common in flowering plants and is believed to be an important force driving adaptation and speciation. The flowers of hybrids often exhibit new trait combinations, which, theoretically, could attract new species of pollinators. In this study, we found that the hybrids between a hummingbird-pollinated species Mimulus cardinalis and a self-pollinated species Mimulus parishii attract bumblebees (Bombus impatiens), a pollinator not attracted to either of the progenitor species. This novel attraction is explained by new combinations of floral traits in hybrids, including, most importantly, petal color, in addition to nectar concentration and corolla size. To understand how petal color variation is perceived by bumblebees, we performed reflectance spectroscopy and multispectral imaging to model the flower appearance in bee vision. This analysis showed that color variation would impact the ease of detection. We also found that YUP, the genetic locus responsible for a large portion of floral color variation and previously shown to be important in bee interactions with other Mimulus species, also played an important role in this novel attraction. These results together suggest that the attraction of new pollinators to hybrid plants could be an underexplored avenue for pollinator shift and speciation.
摘要：
杂交在开花植物中很常见，被认为是推动适应和物种形成的重要力量。杂种的花经常表现出新的性状组合,which,理论上,可以吸引传粉媒介的新物种。在这项研究中,我们发现蜂鸟授粉的物种Mimuluscardinalis和自花授粉的物种Mimulusparishii之间的杂种吸引了大黄蜂（Bombusimpatiens），不被任何一个祖先物种吸引的传粉者。这种新颖的吸引力是通过杂种中花卉性状的新组合来解释的，包括,最重要的是,花瓣颜色,除了花蜜浓度和花冠大小。要了解大黄蜂如何感知花瓣颜色变化，我们进行了反射光谱和多光谱成像来模拟蜜蜂视觉中的花朵外观。该分析表明,颜色变化将影响检测的容易性。我们还发现YUP,负责大部分花色变异的遗传基因座，先前被证明在蜜蜂与其他Mimulus物种的相互作用中很重要，在这部小说中也起了重要的作用。这些结果共同表明，新的传粉媒介对杂交植物的吸引力可能是传粉媒介转移和物种形成的未充分开发的途径。
