Agunbiade T A, Coates B S, Kim K S, Forgacs D, Margam V M, Murdock L L, Ba M N, Binso-Dabire C L, Baoua I, Ishiyaku M F, Tamò M, Pittendrigh B R
Department of Entomology, University of Illinois at Urbana-Champaign, Illinois, USA.
USDA-ARS, Corn Insects and Crop Genetics Research Unit, Ames, Iowa, USA.
Bull Entomol Res. 2012 Oct;102(5):589-99. doi: 10.1017/S0007485312000156. Epub 2012 Apr 17.
The legume pod borer, Maruca vitrata, is an endemic insect pest that causes significant yield loss to the cowpea crop in West Africa. The application of population genetic tools is important in the management of insect pests but such data on M. vitrata is lacking. We applied a set of six microsatellite markers to assess the population structure of M. vitrata collected at five sites from Burkina Faso, Niger and Nigeria. Observed polymorphisms ranged from one (marker 3393) to eight (marker 32008) alleles per locus. Observed and expected heterozygosities ranged from 0.0 to 0.8 and 0.0 to 0.6, respectively. Three of the loci in samples from Nigeria and Burkina Faso deviated significantly from Hardy-Weinberg Equilibrium (HWE), whereas no loci deviated significantly in samples from Niger. Analysis of molecular variance (AMOVA) indicated that 67.3% level of the genetic variation was within individuals compared to 17.3% among populations. A global estimate of F ST=0.1 (ENA corrected F ST=0.1) was significant (P⩽0.05) and corroborated by pairwise F ST values that were significant among all possible comparisons. A significant correlation was predicted between genetic divergence and geographic distance between subpopulations (R2=0.6, P=0.04), and cluster analysis by the program STRUCTURE predicted that co-ancestry of genotypes were indicative of three distinct populations. The spatial genetic variance among M. vitrata in West Africa may be due to limited gene flow, south-north seasonal movement pattern or other reproductive barriers. This information is important for the cultural, chemical and biological control strategies for managing M. vitrata.
豆荚螟（Maruca vitrata）是一种本地害虫，给西非的豇豆作物造成了严重的产量损失。应用群体遗传学工具对于害虫管理很重要，但目前缺乏关于豆荚螟的此类数据。我们应用了一组六个微卫星标记来评估从布基纳法索、尼日尔和尼日利亚的五个地点采集的豆荚螟的群体结构。每个位点观察到的多态性范围从1个等位基因（标记3393）到8个等位基因（标记32008）。观察到的杂合度和预期杂合度范围分别为0.0至0.8和0.0至0.6。来自尼日利亚和布基纳法索的样本中的三个位点显著偏离哈迪-温伯格平衡（HWE），而来自尼日尔的样本中没有位点显著偏离。分子方差分析（AMOVA）表明，67.3%的遗传变异存在于个体内部，而群体间的遗传变异为17.3%。F ST的全局估计值为0.1（ENA校正后的F ST = 0.1），具有显著性（P⩽0.05），并且在所有可能的比较中，成对F ST值也具有显著性，这证实了该结果。预测亚群体之间的遗传分化与地理距离之间存在显著相关性（R2 = 0.6，P = 0.04），并且通过STRUCTURE程序进行的聚类分析预测，基因型的共同祖先表明存在三个不同的群体。西非豆荚螟的空间遗传变异可能是由于基因流动有限、南北季节性移动模式或其他生殖障碍。这些信息对于管理豆荚螟的栽培、化学和生物防治策略很重要。
