MARKER-ASSISTED SELECTION AND MARKER-QTL ASSOCIATIONS IN HYBRID POPULATIONS

A detailed analysis is presented of the relationship between genetic m arkers and quantitative trait loci (QTLs) in the process of marker-ass isted selection (MAS). We simulated MAS employing a multiple linear re gression to chose from among all of the markers in the genome those to be utilized by selection and to estimate their associated effects on the trait. The simulations demonstrate that, even when such selection is quite effective, the markers utilized by selection are not necessar ily the most tightly linked to the QTLs controling the trait. Moreover , the additive effects associated with the markers estimated by the re gression may not accurately reflect the contributions to the trait by the most tightly linked QTLs.