Langzeitselektion bei asymmetrischer Merkmalsverteilung

Abstract. Title of the paper: Long-term selection by asymmetric trait distribution
A quantitative trait is assumed to be genetically affected by a polygenic effect and a major effect of a Single dialellic locus. Such a model is called mixed model of inheritance and the identified gene is denoted as quantitative trait locus (QTL). By choosing the part of the QTL-variance, the degree of dominance and the frequency of the favourable allele it is possible to generate distributions with given level of asymmetry characterised by skewness and kurtosis. If the ratio of QTL- and phenotypic variance is small (less than 8%), then genotype-environment interaction can be used in the mixed inheritance model to explain values of skewness and kurtosis estimated with poultry data. The Situation is considered where the environmental variances given for the three QTL-genotypes show a wide ränge. In most of these cases the short- and long-term selection does not effects the high values for skewness and kurtosis over multiple generations. Further the ratio of response to selection and the difference of selection depends on the selection intensity.