Data from: Reproductive character displacement shapes a spatially structured petal color polymorphism in Leavenworthia stylosa

Character displacement is a potentially important process driving trait evolution and species diversification. Floral traits may experience character displacement in response to pollinator-mediated competition (ecological character displacement) or the risk of forming hybrids with reduced fitness (reproductive character displacement). We test these and alternative hypotheses to explain a yellow-white petal color polymorphism in Leavenworthia stylosa, where yellow morphs are spatially associated with a white-petaled congener (L. exigua) that produces hybrids with complete pollen sterility. A reciprocal transplant experiment found limited evidence of local adaptation of yellow color morphs via increased survival and seed set. Pollinator observations revealed that Leavenworthia attract various pollinators that generally favor white petals and exhibit color constancy. Pollen limitation experiments showed that yellow petals do not alleviate competition for pollination. Interspecific pollinator movements were infrequent and low hybridization rates (~0.40% - 0.85%) were found in each morph, with natural rates likely being lower. Regardless, hybridization rates were significantly higher in white morphs of L. stylosa, yielding a small selection coefficient of s = 0.0042 against this phenotype in sympatry with L. exigua. These results provide support for reproductive character displacement as a mechanism contributing to the pattern of petal color polymorphism in L. stylosa.性状替换（character displacement）是推动性状演化与物种多样化的潜在关键过程。花部性状可能因传粉者介导的竞争（生态性状替换，ecological character displacement），或是产生适合度降低的杂交后代的风险（生殖性状替换，reproductive character displacement）而发生性状替换。本研究针对莱文沃斯荠（Leavenworthia stylosa）的黄白花瓣颜色多态性验证上述及其他备选假说；该物种的黄色花型在空间分布上与开白花的同属近缘种L. exigua共存，二者的杂交后代花粉完全不育。互惠移植实验结果显示，黄色花型通过提升存活率与结籽率实现本地适应的证据较为有限。传粉者观察结果表明，莱文沃斯荠可吸引多种传粉者，此类传粉者普遍偏好白色花瓣且具备颜色恒常性。花粉限制实验显示，黄色花瓣无法缓解传粉竞争。种间传粉者转移事件较为罕见，两种花型的杂交率均处于较低水平（约0.40%~0.85%），自然状态下的杂交率可能更低。尽管如此，莱文沃斯荠的白色花型的杂交率显著更高，在与L. exigua同域分布的情境中，该表型面临选择系数s=0.0042的选择压力。上述结果支持生殖性状替换作为促成莱文沃斯荠花瓣颜色多态性格局的机制之一。