Department of Ecology and Evolutionary Biology, University of Colorado, Boulder Colorado, 80305.
Department of Botany, University of Wisconsin - Madison, Madison, Wisconsin 53706.
Evolution. 2018 Mar;72(3):688-697. doi: 10.1111/evo.13416. Epub 2018 Jan 12.
Flower form is one of many floral features thought to be shaped by pollinator-mediated selection. Although the drivers of variation in flower shape have often been examined in microevolutionary studies, relatively few have tested the relationship between shape evolution and shifts in pollination system across clades. In the present study, we use morphometric approaches to quantify shape variation across the Andean clade Iochrominae and estimate the relationship between changes in shape and shifts in pollination system using phylogenetic comparative methods. We infer multiple shifts from an ancestral state of narrow, tubular flowers toward open, bowl-shaped, or campanulate flowers as well as one reversal to the tubular form. These transitions in flower shape are significantly correlated with changes in pollination system. Specifically, tubular forms tend to be hummingbird-pollinated and the open forms tend to be insect-pollinated, a pattern consistent with experimental work as well as classical floral syndromes. Nonetheless, our study provides one of the few empirical demonstrations of the relationship between flower shape and pollination system at a macroevolutionary scale.
花的形态是被传粉媒介选择塑造的众多花卉特征之一。虽然花的形态在微观进化研究中经常被研究，但是很少有研究检验形态进化与沿进化枝系的传粉系统转变之间的关系。在本研究中，我们使用形态测量方法来量化安第斯山的 Iochrominae 族的形态变异，并使用系统发育比较方法来估计形态变化与传粉系统转变之间的关系。我们推断出从狭窄、管状花的祖先状态向开放、碗状或钟状花以及一个管状花的逆转的多次转变。这些花的形态的转变与传粉系统的变化显著相关。具体来说，管状形式往往是蜂鸟传粉，而开放形式往往是昆虫传粉，这与实验工作以及经典的花型综合征一致。尽管如此，我们的研究提供了在宏观进化尺度上花的形态与传粉系统之间关系的少数实证之一。
