BC_1群体单标记分析检测QTL的效率

Efficiencies of QTL Detection in BC_1 Population by Single Marker Analysis

[目的]为QTL定位中进一步估计QTL的位置和影响效应提供必要的依据。[方法]以BC1设计为资源群体,通过计算机模拟研究了不同群体规模、标记-QTL间图距、性状遗传力和QTL效应(QTL方差占加性遗传方差的比例)对单标记分析检测QTL效率的影响。[结果]表明:资源群体规模较大,标记与QTL的间距较小(或标记与QTL连锁紧密),目标性状的遗传力较高,且QTL效应较大时,采用单标记分析方法检测QTL的检出率较高。当所检测的标记距离QTL较近时,获得相同的QTL检出率所需的资源群体规模更小。[结论]QTL效应对QTL检出率的影响会受性状遗传力的制约,如果性状的遗传力过低,即使QTL方差占遗传方差的比例很高,也很难获得理想的QTL检出率。

【Objective】The purpose was to provide necessary basis for the further evaluating the QTL location and influencing effects in QTL mapping.【Methods】A single marker analysis experiment for QTL detection in a backcross（BC1） population was simulated.The effects of population size,map distance between marker and QTL,trait heritability and the ration of QTL variance to genetic variance on the detecting QTL efficiency were analyzed.【Results】The results showed that it would gain higher QTL detected ratio when the size of resource population was larger,the distance between marker locus and QTL was shorter（i.e.the marker was linked with QTL tightly）,the trait heritability and the QTL effect was higher.The size of resource population demanded for gaining the same QTL detection efficiency would be decreased while the distance of detected marker and QTL was shorter.【Conclusion】It was restricted by the level of trait heritability for the influence of QTL effect on QTL detection efficiency.It was difficult to gain higher detection efficiency,when the heritability was too low,even the QTL accounted for larger proportion of genetic variance.