Data from: The genetic architecture of a complex ecological trait: host plant use in the specialist moth, Heliothis subflexa

We used genetic mapping to examine the genetic architecture of differences in host plant use between two species of noctuid moths, Heliothis subflexa, a specialist on Physalis spp., and its close relative, the broad generalist H. virescens. We introgressed H. subflexa chromosomes into the H. virescens background and analyzed 1,462 backcross insects. The effects of H. subflexa-origin chromosomes were small when measured as the percent variation explained in backcross populations (0.2 to 5%), but were larger when considered in relation to the interspecific difference explained (1.5 to 165%). Most significant chromosomes had effects on more than one trait, and their effects varied between years, sexes, and genetic backgrounds. Different chromosomes could produce similar phenotypes, suggesting that the same trait might be controlled by different chromosomes in different backcross populations. It appears that many loci of small effect contribute to the use of Physalis by H. subflexa. We hypothesize that behavioral changes may have paved the way for physiological adaptation to Physalis by the generalist ancestor of H. subflexa and H. virescens.

本研究采用遗传作图（genetic mapping）技术，探究两种夜蛾科（Noctuidae）实夜蛾属昆虫在寄主植物利用特性差异上的遗传结构：一是专性取食酸浆属（Physalis spp.）植物的亚缘实夜蛾（Heliothis subflexa），其二是其近缘广食性物种烟芽夜蛾（Heliothis virescens）。我们将亚缘实夜蛾的染色体片段回交导入至烟芽夜蛾的遗传背景中，并对1462头回交子代昆虫进行分析。以回交群体中解释的变异百分比（0.2%至5%）为衡量标准时，来自亚缘实夜蛾的染色体效应较小；但以其解释的种间差异占比（1.5%至165%）为参照时，效应则更为显著。多数具有显著效应的染色体可调控多个性状，且其效应在不同年份、性别及遗传背景间存在差异。不同染色体可产生相似的表型，这表明同一性状在不同回交群体中可能由不同染色体调控。现有结果显示，诸多效应较小的基因座参与了亚缘实夜蛾对酸浆属植物的寄主利用过程。本研究提出假说：亚缘实夜蛾与烟芽夜蛾的广食性共同祖先，率先发生了行为改变，进而为其对酸浆属植物的生理适应性演化铺平了道路。