Genetics & Punnet Squares

In both American cotton (Gossypium hirsutum) and Egyptian cotton (G. barbadense)
petal spot is a dominant character over no
petal spot. When the cross is made within
the species, the F2 progeny segregates in a 3:1
ratio with petal spot character in 75% of the
population. However, no clear cut ratio is obtained in respect of the same flower character,
when the cross is made reciprocally between
the above two species.
Which of the following explanation is correct?
1. environmental
2. Error while hybridizing the two species
3. geographical
4. small F2 population
5. Mendel’s laws apply to only varietal
crosses