The effect of non-random mating within inbred lines on the rate of inbreeding

Abstract

Treatment is given of the effect of non-random mating within inbred lines on the rate of decline of heterozygosity, with particular reference to a recent paper on circular mating systems by Kimura and Crow. It is shown that, in mating systems in which mates have a relationship closer than the average for the line, there is a greater initial loss of heterozygosity and a final slower rate of decline, compared to random mating. The reverse is true for systems in which mates are less closely related than average, such as maximum avoidance systems.