Data from: Molecular variability and genetic structure of Chrysodeixis includens (Lepidoptera: Noctuidae), an important soybean defoliator in Brazil

This study provides the first genetic characterization of the soybean looper, Chrysodeixis includens (Walker, 1857), an important defoliating pest species of soybean crops in Brazil. Population genetic variability and the genetic structure of C. includens populations were evaluated by using ISSR markers with samples from the major soybean producing regions in Brazil in the growing seasons 2011/2012. Seven different primers were applied for population characterization of the molecular variability and genetic structure of 8 soybean looper populations from 8 states of Brazil. The seven ISSR loci generated 247 bands in 246 individuals of C. includens sampled. The expected heterozygosity (HE) in the populations varied between 0.093 and 0.106, while the overall HE was 0.099, indicating low genetic diversity. The analysis of molecular variance indicated that 98% of the variability was expressed among individuals within populations (FST = 0.021, p = 0.001). The low level of polymorphism over all populations, the high levels of gene flow, and the low genetic structure are indicatives of the exchange of genetic information between the different sampled regions. Population structuring suggests the presence of two major groups which do not correlate with their geographic sampling location in Brazil. These results may indicate recent recolonization of C. includens in Brazil or migration patterns following source-sink dynamics. Furthermore, the presence of two groups within C. includens suggests that a study on development of resistance or any other genetic-based trait needs to be evaluated on both groups, and pest management in soybean fields should be aware that differences may come to the control strategies they use.本研究首次对巴西大豆作物的重要食叶性害虫——大豆造桥虫（Chrysodeixis includens (Walker, 1857)）开展遗传特征解析。本研究以2011/2012生长季取自巴西主要大豆产区的样本为材料，利用简单序列重复区间扩增多态性（Inter-Simple Sequence Repeat, ISSR）标记，对C. includens种群的遗传变异水平与种群遗传结构进行评估。研究选用7条不同引物，对取自巴西8个州的8个大豆造桥虫种群的分子变异与遗传结构展开分析。7个ISSR位点在246头供试C. includens个体中共扩增得到247个条带。种群内的期望杂合度（Expected Heterozygosity, HE）介于0.093至0.106之间，整体期望杂合度为0.099，表明该害虫的遗传多样性水平较低。分子方差分析结果显示，98%的遗传变异存在于种群内部个体间（FST=0.021，p=0.001）。所有种群均表现出较低的多态性水平、较高的基因流水平以及较弱的遗传结构，这表明不同采样区域间存在遗传信息的交流。种群结构分析显示存在两个主要类群，但该类群划分与采样点的地理分布并无关联。上述结果可能表明C. includens在巴西境内存在近期重新定殖的现象，或是遵循源-汇动态的迁移模式。此外，C. includens种群内存在两个类群的现象提示，针对抗药性发育或其他基于遗传特性的相关研究需同时在两个类群中开展；同时大豆田的害虫防治工作应注意，类群间的差异可能会对其所采用的防控策略产生影响。