The Ewens-Watterson test for neutrality at 7 microsatellite loci in Spodoptera exigua

The Ewens-Watterson test for neutrality of microsatellite markers showed that F-value (sum of square of allelic frequency) lied outside the lower and upper limit of 95% confidence region of expected F value in 3 loci (Spe08, Spe10, Spe12) . According to results of Ewens-Watterson test for neutrality for markers, some loci were not neutral and may be linked with some selection traits. If a neutral allele statistically associated with a selected allele at another locus or genes where selection is operating significantly may be carried along and alleles cannot be separated from their genetic background. This phenomenon is known as hitchhiking. Genetic hitchhiking can be potent force in changing allelic frequency and heterozygosity (Kumar et al. 2009).

针对微卫星标记（microsatellite markers）的Ewens-Watterson中性检验（Ewens-Watterson test）结果显示，3个位点（Spe08、Spe10、Spe12）的F值（等位基因频率平方和）超出了预期F值95%置信区域的上下限范围。基于上述标记中性检验的结果，部分位点不符合中性进化特征，且可能与某些选择性状存在连锁关联。若某中性等位基因（neutral allele）与另一位点或受显著选择作用的基因上的选择等位基因（selected allele）存在统计学关联，则该中性等位基因可能会被一同携带，且无法与其自身的遗传背景相分离，这一现象被称为遗传搭车（genetic hitchhiking）。遗传搭车效应是改变等位基因频率与杂合度（heterozygosity）的强效驱动力（Kumar等，2009）。