MAPPING QTLS FOR BINARY TRAITS IN BACKCROSS AND F2 POPULATIONS

Mapping quantitative trait loci (QTLs) for binary traits in backcross and F-2 populations was investigated using stochastic stimulation. Dat a were analysed using either linear regression or a generalized linear model. Parameters which were varied in the simulations were the popul ation size (200 and 500), heritability in the backcross or F-2 populat ion (0.01, 0.05, 0.10), marker spacing (10 and 20 cM) and the incidenc e of the trait (0.50, 0.25, 0.10). The methods gave very similar resul ts in terms of estimates of the QTL location and QTL effects and power of QTL detection, and it was concluded that in practice treating the zero-one data as continuous and using standard linear regression was e fficient.