Modeling the GCA by location interaction for the diallel in ASReml requires some additional tricks. We want to overlay the design matrix for female by location interaction on to that for male by location interaction using the and() model specification. However, we cannot do this directly, because the interaction term ‘location.male’ must be first defined before it is inserted inside the and() specification. This is best explained by example; the model in ASReml is as follows:
Adding GCA-by-environment interaction to model for half diallel using pedigree information on parents (Continued Code05-2_diallels_with_pedigree.as)