Data from: Multiple reproductive barriers separate recently diverged sunflower ecotypes

Measuring reproductive barriers between groups of organisms is an effective way to determine the traits and mechanisms that impede gene flow. However, to understand the ecological and evolutionary factors that drive speciation, it is important to distinguish between the barriers that arise early in the speciation process and those that arise after speciation is largely complete. In this paper we comprehensively test for reproductive isolation between recently diverged (< 10,000 years bp) dune and non-dune ecotypes of the prairie sunflower, Helianthus petiolaris. We find reproductive barriers acting at multiple stages of hybridization, including premating, postmating-prezygotic, and postzygotic barriers, despite the recent divergence. Barriers include extrinsic selection against immigrants and hybrids, a shift in pollinator assemblage, and post-pollination assortative mating. Together these data suggest that multiple barriers can be important for reducing gene flow in the earliest stages of speciation.定量测定生物类群间的生殖隔离屏障，是解析阻碍基因流（gene flow）的性状与作用机制的有效手段。然而，若要阐明驱动物种形成的生态与演化动因，则需区分物种形成早期产生的隔离屏障与物种形成基本完成后才形成的隔离屏障。本研究针对草原向日葵（Helianthus petiolaris）距今不足1万年（bp，即before present）分化形成的沙丘生态型（ecotype）与非沙丘生态型，开展了全面的生殖隔离检测。尽管两类生态型的分化时间极短，但本研究发现二者间存在作用于杂交多个阶段的生殖隔离屏障，涵盖交配前隔离（premating）、交配后合子前隔离（postmating-prezygotic）以及合子后隔离（postzygotic）。这些隔离屏障包括针对迁入个体与杂交后代的外在选择、传粉者群落组成的转变，以及授粉后选型交配。综合本研究数据可知，在物种形成的初始阶段，多重生殖隔离屏障即可对阻碍基因交流发挥关键作用。