A cross of sandhyamalati (Mirabilis jalapa) with a red flower (RR) and a white flower (rr) resulted in pink flowers (Rr) in the F1 line. Self-fertilization between the pink (Rr) flowers of the F1 progeny produced 1 red (25%), 2 pink (50%) and 1 white (25%) flowers in the F2 progeny.
here,
The gene responsible for red color is R
Hence, the red genotype is RR
again,
The gene responsible for white color is r
Consequently, the genotype of white color is rr
The first progeny is F1 and the second progeny is F2
Parents : ♂ × ♀
Phenotype: Red and white
Genotype : RR rr
Gamit : (R) (r)
F1 Lineage : Rr (Pink)
Svanishek : F1×F1
Parents : ♂ × ♀
Phenotype: pinkish pink
Genotype : Rr Rr
Gamit : (R) (r) (R) (r)
F2 progeny (checker board)
Comment: It can be seen from the checker board, out of 4 flowers, 1 is red, 2 are round and 1 is white. Flowers are pink rather than red due to incomplete expression of the expression gene R.
Phenotypic ratio : Red : Pink : White = 1:2:1