In pumpkin, gene A – defines a white fruit, a – a yellow fruit, gene B defines an oval fruit, and B – a round one.

In pumpkin, gene A – defines a white fruit, a – a yellow fruit, gene B defines an oval fruit, and B – a round one. What splitting can be expected when crossing two plants with heterozygous traits? Name the genotypes and phenotypes of F1

From the condition of the problem, we conclude that the white color of the fruit and the oval shape are dominant traits, and the yellow color of the fruit and the round shape are recessive traits. The genotype of both parental plants is AaBb – they are heterozygous for both traits. Consider the possible variants of the F1 genotype and phenotype when crossing plants with the following genotypes:

R: AaBb (white, oval) x AaBb (white, oval)
G: AB, Ab, aB, ab; AB, Ab, aB, ab
F1:

AABB (white, oval)
ААВв (white, oval)
AaBB (white, oval)
AaBb (white, oval)
ААВb (white, oval)
AAbb (white, round)
AaBb (white, oval)
Aabb (white, round)
AaBB (white, oval)
AaBb (white, oval)
aaBB (yellow, oval)
aaBb (yellow, oval)
AaBb (white, oval)
Aabb (white, round)
aaBb (yellow, oval)
aabb (yellow, round)

With such a crossing, the splitting is always 9: 3: 3: 1, i.e. 9 parts of all descendants will be with white oval fruits, 3 parts with white round fruits, 3 more parts with yellow oval fruits and 1 part with yellow round fruits.