Data from: Postmating isolation and genetically variable host use in ecologically divergent host forms of Neochlamisus bebbianae leaf beetles

Ecological speciation studies have more thoroughly addressed premating than postmating reproductive isolation. This study examines multiple postmating barriers between host forms of Neochlamisus bebbianae leaf beetles that specialize on Acer versus Salix trees. We demonstrate cryptic isolation and reduced hybrid fitness via controlled matings of these host forms. These findings reveal host-associated postmating isolation, although a non-ecological, ‘intrinsic’ basis for these patterns cannot be ruled out. Host preference and performance results among cross types further suggest sex-linked maternal effects on these traits, while family effects indicate their genetic basis and associated variation. Genes of major effect appear to influence these traits. Together with previous findings of premating isolation and adaptive differentiation in sympatry, our results meet many assumptions of ‘speciation with gene flow’ models. Here, such gene flow is likely asymmetric, with consequences for the dynamics of future ecological divergence and potential ecological speciation of these host forms.

生态物种形成（ecological speciation）领域的研究对交配前生殖隔离的探讨已较为深入，而针对交配后生殖隔离的分析则相对不足。本研究聚焦于专性寄生槭属（Acer）与柳属（Salix）植物的贝氏扁叶甲（Neochlamisus bebbianae）不同寄主型之间的多种交配后生殖屏障。通过对这些寄主型开展受控交配实验，我们证实了隐蔽隔离现象以及杂交适合度的显著降低。研究结果揭示了寄主关联型交配后生殖隔离的存在，尽管无法排除这些隔离模式存在非生态性‘内在’机制的可能性。不同杂交组合下的寄主偏好性与表现性状结果进一步表明，这些性状存在性连锁母本效应；而家系效应则印证了其遗传基础及相关遗传变异。主效基因（major effect genes）似乎对这些性状具有调控作用。结合此前关于同域种群中交配前生殖隔离与适应性分化的研究发现，本研究结果符合‘存在基因流的物种形成’模型的诸多核心假设。此类基因流大概率呈不对称分布，这将对这些寄主型未来的生态分化动态以及潜在的生态物种形成过程产生重要影响。