Data from: Patterns of genetic variation among geographic and host-plant associated populations of the peach fruit moth Carposina sasakii (Lepidoptera: Carposinidae)

Background: Populations of herbivorous insects may become genetically differentiated because of local adaptation to different hosts and climates as well as historical processes, and further genetic divergence may occur following the development of reproductive isolation among populations. 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 populations from seven plant hosts and nine regions using 19 microsatellite loci and a mitochondrial sequence. Results: 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. Approximate Bayesian Computation analyses supported the scenario that PFM likely originated from a southern area and dispersed northwards before the last glacial maximum during the Quaternary. Conclusions: Our analyses suggested a strong impact of geographical barriers and historical events rather than host plants on the genetic structure of the PFM; however, uncharacterized 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.

背景：植食性昆虫种群可因对不同寄主、气候的本地适应及历史进程发生遗传分化，种群间生殖隔离形成后，还可能产生进一步的遗传分歧。本研究针对中国果园害虫桃小食心虫（peach fruit moth, PFM，学名*Carposina sasakii*，鳞翅目：蛀果蛾科（Carposinidae））展开，该昆虫在不同寄主植物上表现出显著生物学差异。研究采用19个微卫星位点（microsatellite loci）与一段线粒体序列（mitochondrial sequence），对来自7种植物寄主、9个地理区域的种群开展遗传多样性与遗传结构评估。
结果：不同地理区域的地理种群间存在显著遗传分化，但同一区域内采集的寄主关联种群间未检测到此类分化。基于微卫星位点的曼特尔检验（Mantel test）结果显示，遗传分化与地理距离显著相关，与环境分化的相关性相对较弱。近似贝叶斯计算（Approximate Bayesian Computation）分析支持如下演化情景：桃小食心虫可能起源于南方区域，并在第四纪末次冰盛期（last glacial maximum）前向北扩散。
结论：本研究分析表明，地理屏障与历史事件而非寄主植物对桃小食心虫的种群遗传结构具有显著影响；但尚未明确的环境因素与寄主植物或也发挥一定作用。针对该蛾类适应性演化的相关研究，应将地理与历史因素纳入考量范畴。