Adaptive significance of amylase polymorphism in Drosophila. VIII. Effect of carbohydrate dietary components on alpha-amylase activity and Amy-electromorph frequency in Drosophila busckii.

Laboratory populations of D. busckii flies were kept for one generation on media containing different carbohydrate sources (maltose and rice, potato or maize starch). The flies maintained on standard potato medium served as a control. Progeny were analyzed for alpha-amylase activity and Amy-electromorph frequencies. Spectrophotometrically assayed amylase activity was highest in the flies cultured on potato starch medium and lowest in specimens kept on maltose. Carbohydrate source in some substrates affected both frequencies of Amy-alleles and Amy-genotypes. Phenotypic differences at a biochemical level, i.e. in alpha-amylase activity, might be connected to Amy-structural gene polymorphism in the examined Drosophila species.