Data from: Genetic differentiation among populations of the peach fruit moth Carposina sasakii (Lepidoptera: Carposinidae): host adaptation or geographical isolation?

Genetic differentiation among populations of herbivorous insects is an essential component of local adaptation and the development of reproductive isolation. The contributions of geographical, historical and ecological factors to genetic differentiation can be difficult to distinguish due to the absence of historical data and relevant ecological information. Here we investigate the population genetic structure of the orchard pest peach fruit moth (PFM) Carposina sasakii (Lepidoptera: Carposinidae) in China, which shows distinct biological differences when characterized from different host plants. Genetic diversity and genetic structure were assessed among 14 populations from seven plant hosts and nine regions using 19 microsatellite loci and a mitochondrial sequence. Strong genetic differentiation was found among geographical populations representing distinct geographical regions, but not in host-associated populations collected from the same area. Mantel tests based on microsatellite loci indicated an association between genetic differentiation and geographical distance, and to a lesser extent environmental differentiation. DIYABC analyses supported that the PFM likely originated from a southern area and dispersed northwards before the last glacial maximum during the Quaternary. Our analyses suggested a strong impact of geographical barriers and historical events on the genetic structure of the PFM; however, other environmental factors and host plants may also play a role. Studies on adaptive shifts in this moth should take into account geographical and historical factors.

植食性昆虫种群间的遗传分化是本地适应与生殖隔离形成的关键组成部分。受限于历史数据与相关生态信息的缺失，地理、历史及生态因子对遗传分化的相对贡献往往难以区分。本研究以中国境内的果园害虫桃蛀果蛾（peach fruit moth, PFM）*Carposina sasakii*（鳞翅目：蛀果蛾科）为研究对象，该虫不同寄主种群间存在显著生物学差异。研究采集了覆盖7种寄主植物、9个地理区域的14个种群，借助19个微卫星位点（microsatellite loci）与一段线粒体序列（mitochondrial sequence），对其遗传多样性及种群遗传结构进行了解析。结果显示，来自不同地理区域的种群间存在强烈遗传分化，但同区域内不同寄主关联种群间则无显著分化。基于微卫星位点的曼特尔检验（Mantel test）表明，遗传分化与地理距离显著相关，与环境分化的相关性则相对较弱。DIYABC分析结果支持桃蛀果蛾可能起源于南方区域，并在第四纪末次冰盛期前向北扩散。本研究结果提示，地理屏障与历史事件对桃蛀果蛾的种群遗传结构具有显著影响，但其他环境因子与寄主植物也可能发挥一定作用。针对该蛾类适应性演化的相关研究，需将地理与历史因子纳入考量范畴。