Detection of genic interactions by analyzing the F2 generation of diallel crosses

Summary The ability of the Hayman and Jinks method of analysis of diallel crosses to detect genic interactions was studied in peanuts. Six traits, measured in the F₂ generation of a diallel cross of four cultivars, were analyzed. In F₂ analyses of the diallel, least squares estimates of variance components D, H₁ , H₂, F, E, were used as an additional criteria for the adequacy of the diallel model. They were found to be in substantial agreement with the tests based on W_r and V_r values, and probably more reliable. The regression of W_r on V_r was shown to be unsuitable to detect duplicate gene type of interactions; it was detected, however, by the ratio of the mean within-F₂ — family variance and the variance among the parents. Using the different criteria, duplicate genes type of interactions was detected for two traits, complementary genes type was detected for one trait and three traits were found to fit the additive-dominance model without any genic interactions.