In a species of melons there is a dominantly epistatic gene

In a species of melons, there is a dominantly epistatic gene \"E\" that interacts with a hypostatic gene that has two alleles, the dominant \"P\" allele for purple color and recessive \"p\" for green color. The epistatic gene (E_) will cause white melons regardless of the hypostatic genotype. If a heterozygote for both genes is mated with a homozygous dominant for the hypostatic gene who is heterozygous for the epistatic gene, what would be the expected phenotypic ratios from this mating?

I guess im thrown of by the hypostatic part, what would the cross look like and why?

Solution

If a heterozygote for both genes is mated with a homozygous dominant for the hypostatic gene who is heterozygous for the epistatic gene. The cross would like this

PpEe x PPEe

Gametes: PE, pE, Pe, pe; PE, Pe

Offsprings:

PPEE purple melons PPEe White melons

PpEE purple melons PpEe White melons

PPEe White melons PPee Purple melons

PpEe White melons Ppee purple melons

The phenotypic ratio is Purple:White 1:1