Theory of Heterosis

Abstract

The theory of heterosis is expressed by simple genetic models. Relevant population means are deduced for differences in gene frequencies among populations. Heterosis for the one-locus, two-allele model is a function of the square of the difference in gene frequency multiplied by the dominance deviation. Heterosis, for a model with two loci and two alleles at each, contains an additive by additive epistatic term as well. Recombination loss in the F2 or the mating of similar crosses interse is a function of the recombination fraction between loci, differences in gene frequencies, and additive by additive and dominance by dominance epistatic effects. © 1985, American Dairy Science Association. All rights reserved.