基于性状-标记回归的QTL区间测验方法

Methods of QTL Interval Test Based on Trait-Marker Regression

本文提出了两种基于性状-标记回归的QTL区间测验方法，分别称为TMRIT-I和TMRIT-II。前者采用似然比统计量进行显著性测验，与基于最小二乘的简化复合区间定位法（sCIM）等价，但计算上明显简单快捷；后者则采用一种“伪似然比” 统计量进行显著性测验，不仅进一步简化计算，而且明显提高统计功效。二者皆可通过排列测验估计显著阈值。给出了一个模拟例子。

Two methods of interval test of quantitative trait loci (QTLs) based on trait-ma rker regression are proposed, named as TMRIT-I and TMRIT-II, respectively. The f ormer uses likelihood ratio statistic for significance test, equivalent to the m ethod of simplified composite interval mapping (sCIM) based on least squares, bu t much simpler and quicker in calculation. The latter uses a ‘pseudo-likelihood ratio’ statistic for significance test, not only simplifying calculation furth er, but also significantly increasing statistical power. For both methods, signi ficance threshold can be estimated by permutation tests. A simulated example is given.