Effects of parental age and sampling method on response to index selection in Tribolium castaneum

Abstract

Two generations of individual selection on the basis of an index incorporating the 13th day larval weight and pupal weight were carried out using Triboliumcastaneum. The experimental design consisted of two sampling methods by three parental ages and was repeated three times concurrently (three sets). Eight offspring for each of 10 families per set were measured. Heritabilities and phenotypic and genetic correlations for larval and pupal weights were estimated using variance components. Age of parents had an effect on response to selection for total merit. Offspring of older parent stocks had heavier larval weight. Sampling parents from one subpopulation versus sampling from a group of subpopulations had no consistent effect on total merit. Although the overall effect of set was not significant, interactions of set with sampling method and parental age were significant, indicating that control of these factors might reduce among replicate variation commonly seen in selection experiments.