Answer:
AaBb
Explanation:
In the given dihybrid cross, the genotype of one parent plant is AABB and that of the other parent plant is aabb. The parent plant with the "AABB" genotype would form all the gametes having "AB" alleles. The parent plant with "aabb" genotype would form all the gametes having "ab" alleles. The random fusion of the gametes from the two parents would produce all the progeny of F1 having the genotype "AaBb".
Therefore, the F1 generation would be heterozygous dominant for both the genes under study.
Cross: AABB x aabb= AaBb