Abstract
The genetic structure of the four-way crossbred chickens Nohrin 101, their parental crossbreds 62×11 and 21×12 and the original strains 11, 12, 21 and 62 were examined. Six polymorphic loci, blood group A, B, D and G, plasma esterase (Es-1) and alkaline phosphatase (Akp) were analyzed.
Gene frequencies at the blood group B, plasma esterase and alkaline phosphatase loci were considerably different among the strains, but those at the blood group A, D and G loci showed similar values. The genetic distances between the strains and between the two-way crossbreds were estimated. It was concluded that the largest genetic distance was expected on the present cross-combination (62•11×21•12). The significance of genetic distance in the breeding for heterosis was discussed.
