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 F 2 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.