Population Genetic Effects of Inbreeding

Because of the agronomic importance of self-fertilizing crops, some population genetic effects of continued selfing will be considered. Also other inbreeding systems, e.g. parent × offspring mating and full sib mating, will get attention. Continued inbreeding yields populations consisting of a mixture of plants with homozygous genotypes. The decrease of the frequency of heterozygous plants is described for both diploid and autotetraploid crops. It is shown that continued inbreeding eventually leads to a genotypic composition which is approximately determined by the initial haplotype frequencies. As perfect selfing is an idealization, also some attention is given to reproduction by means of a mixture of self-fertilization and cross-fertilization.