Null Hypothesis is that "In the F2 generation resulting from the cross of F1 generation parent plants that were heterozygous for both kernel color (Aa) and texture (Ee), the phenotypic ratio of endosperm content and aleurone pigmentation will follow a 9:3:3:1 ratio.
In the context of Mendelian genetics, when considering two traits controlled by different genes on separate chromosomes that assort independently, the null hypothesis for the expected phenotypic ratio in the F2 generation is based on the principle of independent assortment. This means that the alleles for each gene segregate independently during gamete formation.
For simplicity, let's denote the alleles for endosperm content by E and e, and for aleurone pigmentation by A and a. The null hypothesis for the expected phenotypic ratio in the F2 generation would be based on the assumption that these alleles segregate independently of each other.