Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, New England Biolabs, 430079, China.
New Phytol. 2019 Nov;224(3):1142-1150. doi: 10.1111/nph.16012. Epub 2019 Jul 22.
Visual signals attractive to friends may also attract enemies. The bright colors of anthers and pollen have generally been thought to attract pollinators. We hypothesize that visual crypsis of anthers, and particularly pollen, should be favored in flowering plants because protection from pollen collectors reduces the loss of male gametes. To understand adaptive strategies relating to the color of pollen, we measured the color of pollen, undehisced anther sacs, and their background, the corolla, with a spectrometer for 104 insect-pollinated flowering species from a natural community in Hengduan Mountains, southwest China. The colors of anthers, pollen and corollas were diverse in these species. The color diversity of exposed pollen was significantly higher than that of concealed pollen (i.e. where anthers are enclosed or shielded by corollas). The color contrast between pollen and corolla was significantly smaller in species with exposed pollen than in those with concealed pollen. Unlike anther color, exposed pollen color tended to match its background corolla color. Our phylogenetic comparative analysis showed contrasting effects of pollen color patterns between flowers with exposed pollen and those with concealed pollen, revealing a strategy of hiding pollen from pollen thieves via visual crypsis.
对朋友有吸引力的视觉信号也可能吸引敌人。通常认为，花粉囊和花粉的鲜艳颜色可以吸引传粉者。我们假设，花中花粉囊，尤其是花粉，应该有视觉伪装，因为这样可以防止花粉采集者造成的雄性配子损失。为了了解与花粉颜色有关的适应策略，我们使用分光光度计测量了来自中国西南横断山区自然群落中的 104 种昆虫传粉的开花植物的花粉、未开裂的花粉囊及其背景花被（花瓣）的颜色。这些物种的花粉、花粉囊和花瓣颜色多样。暴露的花粉颜色多样性显著高于隐蔽的花粉（即，花粉囊被花瓣包裹或遮挡）。暴露花粉的花粉与花瓣之间的颜色对比在具有暴露花粉的物种中明显小于具有隐蔽花粉的物种。与花粉囊颜色不同的是，暴露的花粉颜色往往与其背景花瓣颜色相匹配。我们的系统发育比较分析显示，具有暴露花粉的花朵和具有隐蔽花粉的花朵之间的花粉颜色模式存在相反的影响，这揭示了一种通过视觉伪装来隐藏花粉以防止花粉盗窃者的策略。
