On the mapping of QTL by regression of phenotype on marker-type

We consider the properties of the regression of phenotype on marker-type in Fz and backcross populations. We show that this regression provides exactly the same information about the location and effect of QTL as conventional regression mapping. For certain QTL configurations this information is insufficient to map the QTL. Where the QTL can be mapped, the position and effect of QTL can be estimated directly from the coefficients of the regression of phenotype on marker-type. This requires much less computational effort than conventional regression mapping. Examples are given to illustrate the development of the theory.