性状遗传力与QTL方差对标记辅助选择效果的影响

在采用动物模型标记辅助最佳线性无偏预测方法对个体育种值进行估计的基础上，模拟了在一个闭锁群体内连续对单个性状选择10个世代的情形，并系统地比较了性状遗传力和QTL方差对标记辅助选择所获得的遗传进展、QTL增效基因频率和群体近交系数变化的影响。结果表明：在对高遗传力和QTL方差较小的性状实施标记辅助选择时，可望获得更大的遗传进展；遗传力越高，QTL方差越大，则QTL增效基因频率的上升速度越快；遗传力较高时，群体近交系数上升的速度较为缓慢，而QTL方差对群体近交系数上升速度的影响则不甚明显。结合前人关于标记辅助选择相对效率的研究结果，可以认为：当选择性状的遗传力和QTL方差为中等水平时，标记辅助选择可望获得理想的效果。

Effects of Trait Heritability and QTL Variance on Marker-assisted Selection

A ten generation of continuous selection experiment on a single trait in a closed population was simulated.Individual breeding values were estimated through animal model marker assisted best linear unbiased prediction (MBLUP).The effects of trait heritability and QTL variance on genetic response,change of favorable QTL allele frequency and inbreeding coefficient from marker assisted selection (MAS) were analyzed.The results showed that higher genetic response would be gained when MAS is implemented on those traits with higher heritability and smaller QTL variance;the favorable QTL allele frequency would increase faster with the higher heritability and larger QTL variance;when the heritability was higher,the inbreeding coefficient would increase slower,but QTL variance has less effect on it.Considering the absolute effect and relative efficiency of MAS, we hold the point that it is expected to gain satisfied effects when MAS is implemented on those traits with medium heritability and QTL variance.