Answer to Question #125781 in Genetics for Ria Tanna

Question

In sesame, the one-pod condition (P) is dominant over the three-pod condition (p) and normal leaf (L) is dominant over wrinkled lead (1). Determine the genotype and phenotype of the two parents that produce the following progeny: 318 one-pod normal leaf, 98 one-pod wrinkled leaf, 323 three-pod normal leaf, and 104 three-pod wrinkled leaf.

Answer 1

a)323 one-pod normal and 98 one-pod wrinkled

   If one parent is homozygous dominant for the one-pod trait (PP), then mating with any of the other possible genotypes will give all one-pod phenotypes (PP or Pp). This appears to be a 3:1 phenotype for the leaf shape focus. This phenotype is the result of two heterozygotes mating (Ll×Ll)

Therefore, the Parental Genotypes are PPLl×PPLl

 b)323 three-pod normal leaf and 104 three-pod wrinkled leaf.

 All offspring are three-pod and it is a recessive trait. Therefore, both parents must be homozygous recessive for this gene(pp×pp).

This appears to be a 3:1 phenotype for the leaf shape focus. This phenotype suggests a cross between two heterozygotes (Ll×Ll).

 Therefore, the Parental Genotypes are ppLl×ppLl