Department of Biological Sciences, University of Wisconsin - Milwaukee, Milwaukee, WI, USA.
Department of Plant Biology, University of Georgia, Athens, GA, USA.
J Evol Biol. 2021 May;34(5):803-815. doi: 10.1111/jeb.13781. Epub 2021 Mar 27.
Variation in selfing rates within and among populations of hermaphroditic flowering plants can strongly influence the evolution of reproductive strategies and the genetic structure of populations. This intraspecific variation in mating patterns may reflect both genetic and ecological factors, but the relative importance of these factors remains poorly understood. Here, we explore how selfing in 13 natural populations of the perennial wildflower Mimulus ringens is influenced by (a) pollinator visitation, an ecological factor, and (b) floral display, a trait with a genetic component that also responds to environmental variation. We also explore whether genetically based floral traits, including herkogamy, affect selfing. We found substantial variation among populations in selfing rate (0.13-0.55). Selfing increased strongly and significantly with floral display, among as well as within populations. Selfing also increased at sites with lower pollinator visitation and low plant density. However, selfing was not correlated with floral morphology. Overall, these results suggest that pollinator visitation and floral display, two factors that interact to affect geitonogamous pollinator movements, can influence the selfing rate. This study identifies mechanisms that may play a role in maintaining selfing rate variation among populations.
雌雄同体开花植物种群内和种群间的自交率变化会强烈影响生殖策略的进化和种群的遗传结构。这种交配模式的种内变异可能反映了遗传和生态因素，但这些因素的相对重要性仍知之甚少。在这里，我们探讨了多年生野花双色金光菊的 13 个自然种群中的自交受哪些因素影响：(a) 传粉者访问，这是一个生态因素；(b) 花部展示，这是一个具有遗传成分的特征，也会对环境变化做出响应。我们还探讨了基于遗传的花部特征（包括雌雄蕊异长）是否会影响自交。我们发现自交率在种群间存在显著差异（0.13-0.55）。在种群内和种群间，自交率随花部展示的增加而显著增加。自交率在传粉者访问较少和植物密度较低的地点也有所增加。然而，自交率与花部形态无关。总的来说，这些结果表明，传粉者访问和花部展示这两个因素会影响异交传粉者的运动，它们相互作用，会影响自交率。本研究确定了可能在维持种群间自交率变异中起作用的机制。
