DYNAMIC STUDY OF GENOTYPE-ENVIRONMENT INTERACTION WITH EGG-LAYING OF TRIBOLIUM-CASTANEUM

Within-line family selection was carried out at an optimum (33.degree. C) and 2 stress temperatures (28.degree. C and 38.degree. C) for increasing egg number laid by virgin females of T. castaneum from the 7th to the 11th day after adult emergence. A control was maintained. Two replicated lines were selected at each temperature, and all selected lines were tested in each of the 3 environments. Direct and correlated responses to selection in different environments were analyzed to study implications of genotype-environment interaction on the selection outcome. Although selection at the optimum environment was the most effective, it did not confer the specialization needed for performance in stress environments. Selecting in adverse environments led to a broader range of performance over environments, which in one case (38.degree. C) included the optimum one. The degree of adaptation to adverse environments was mainly determined by the magnitude of the genetic correlation between performances in the adverse and the optimum environments. The evolution of such correlations through selection was also investigated.