[Mapping by molecular markers showing segregation distortion]

The comparative analysis of segregation distortions of the codominant markers data presented in software MAPMAKER are made, where five RFLPs markers involve in a mouse F2 population with 333 individuals. The successive chi(2) test begins with the determinations of gametic or zygotic selection types, followed by the estimation of recombination fractions between two markers with the Newton-Raphson iteration method. It is better to use the molecular marker showing segregation distortion for constructing a genetic map, in the case of seriously skew segregation between both the adjoining markers. The successive chi(2) test provides better accuracy than that of classical chi(2) test for the estimation of the recombination values in F2 population with segregation distortion.