Abstract
Analysis of a barley population in terms of changes in genotypic frequencies occurring over 18 generations, under a mating system involving predominant self-fertilization, indicated that decay in heterozygosity was slower at several marker loci than expected for the observed amount of outcrossing. These results were explained on the basis of heterozygote advantage associated with segments of chromosomes. It was postulated that heterozygote advantage may have important adaptive implications in the maintenance of population variability, and hence in the evolutionary potential of self-fertilizing species.