The effect of gene–environment interaction

The phenotype determined by a single gene with codominant alleles can be modified by the action of environmental factors The phenotype determined by a single gene with codominant alleles can be modified by the action of environmental factors

(a) No gene—environment (b) Moderate gene— (c) Substantial gene— interaction environment interaction environment interaction P A1A1 AzAz A1A1 AzAz A1A1 2 2 ‘i—I—i—i—Lr M A1A2 A,A2 AiAz AA; A A discrete phenotype for |Minor overlaps between Wide phenotypic ranges each genotype |'phenotypes in the F and significant overlaps