Abstract
Using the relation of genotype-location and error variances between half-sib families and I1 lines in rye, the efficiency of selection based on I1 lines per se in comparison with half sib family selection is investigated. It is concluded that selection on the performance of I1 lines could be advantageous especially in cases of higher degrees of dominance and gene frequencies of the favourable genes higher than 0,5. The difficulties caused by the strong self-incompatibility in rye and possible ways of overcoming them are discussed.