不同遗传力和标记密度下QTL区间定位的效果

Effects of Interval Mapping for Quantitative Trait Loci under Different Heritabilities and Marker Densities

采用计算机模拟方法系统比较了目标数量性状的遗传力和标记密度对F2设计下单个性状数量性状座位（QTL）区间定位效果的影响。研究结果表明：随着性状遗传力的升高，QTL的检测效率以及QTL位置估计的准确性和精确性也提高，但对QTL加性效应和显性效应估计的效果则无明显影响；在一定范围内提高遗传图谱上的标记密度对保证QTL的定位效果具有积极的意义，但当相邻标记间的图距缩小到一定程度（5-10cM）时，进一步增加标记密度并不能改进QTL定位的效果。同时，对遗传力过低的性状实施QTL定位，单纯增加标记密度无益于改进QTL定位的效果。

The effects of interval mapping for quantitative trait loci （QTL） of single trait under different heritabilities and marker densities in a F2 population were compared by computer simulation. The results showed that with the increase of heritability, the detection power would be increased, and accompany with the increase of the accuracy and precision of QTL position estimation, however it had no obvious influence on the estimation of QTL additive and dominance effects. It was important to ensure the effect of QTL mapping by increasing marker density in a certain extent, but as the map distance between two adjacent markers reach to a certain degree （5-10 cM）, it could not improve the result of QTL mapping by further increasing marker density. In additional, when mapping QTL for the trait with lower heritability, it had no obvious benefit to the QTL mapping by simply increasing marker density.