Data from: The genetic architecture of ecological adaptation: intraspecific variation in host plant use by the lepidopteran crop pest Chloridea virescens

Intraspecific variation in ecologically important traits is the cornerstone of Darwin’s theory of evolution by natural selection. The evolution and maintenance of this variation depends on genetic architecture, which in turn determines responses to natural selection. Some models suggest that traits with complex architectures are less likely to respond to selection than those with simple architectures, yet rapid divergence has been observed in such traits. The simultaneous evolutionary lability and genetic complexity of host plant use in the Lepidopteran subfamily Heliothinae suggest that architecture may not constrain ecological adaptation in this group. Here we investigate the response of Chloridea virescens, a generalist that feed on diverse plant species, to selection for performance on a novel host, Physalis angulata (Solanaceae). P. angulata is the preferred host of Chloridea subflexa, a narrow specialist on the genus Physalis. In previous experiments, we found that the performance of C. subflexa on P. angulata depends on many loci of small effect distributed throughout the genome, but whether the same architecture would be involved in the generalist’s adoption of P. angulata was unknown. Here we report a rapid response to selection in C. virescens for performance on P. angulata, and establish that the genetic architecture of intraspecific variation is quite similar to that of the interspecific differences in terms of the number, distribution, and effect sizes of the QTL involved. We discuss the impact of genetic architecture on the ability of Heliothine moths to respond to varying ecological selection pressures.

生态重要性状的种内变异，是达尔文自然选择进化论的核心基石。此类变异的演化与维持依赖于遗传架构（genetic architecture），而遗传架构反过来又决定了种群对自然选择的响应能力。部分模型显示，相较于遗传架构简单的性状，遗传架构复杂的性状更难响应选择，但已有研究在这类性状中观测到了快速分化现象。鳞翅目（Lepidoptera）实夜蛾亚科（Heliothinae）的寄主植物利用性状同时兼具演化易变性与遗传复杂性，这表明遗传架构或许不会限制该类群的生态适应。

本研究以可取食多种植物的广食性物种*Chloridea virescens*为对象，探究其在新型寄主*Physalis angulata*（茄科Solanaceae）上的适合度表现对选择压力的响应。*Physalis angulata*是专性取食酸浆属（*Physalis*）植物的狭食性物种*Chloridea subflexa*的偏好寄主。在过往实验中，我们发现*Chloridea subflexa*在*Physalis angulata*上的适合度表现由遍布全基因组的多个微效基因座所决定，但尚不清楚广食性物种*Chloridea virescens*接纳*Physalis angulata*的过程是否涉及相同的遗传架构。

本研究结果显示，*Chloridea virescens*在*Physalis angulata*上的适合度表现对选择压力产生了快速响应；同时证实，在所涉及的数量性状基因座（QTL）的数量、分布及效应大小层面，种内变异的遗传架构与种间差异的遗传架构极为相似。我们还讨论了遗传架构对实夜蛾亚科蛾类响应不同生态选择压力的能力所产生的影响。