COMPARISON OF FAMILY AND SIB SELECTION DURING SELFING

Theory is presented and subsequently validated by computer simulation for predicting the difference in response to family and sib selection during selfing. The response is measured by the change in mean and var iance of the distribution of inbred lines due to selection. A combined measure of the response is also given by the proportion of lines scor ing higher or lower than a given target. Simulation of a highly herita ble character under simple genetic control demonstrated the reliabilit y of the theory. However, with a character of moderate heritability in volving additive and nonadditive effects, and experimental sizes more common in practice, the differences between family and sib selection p roved to be small. This was further confirmed by the sampling variatio n of the responses.