Answer:
100% red kernel color
Step-by-step explanation:
R_B_ = Red kernel color
R_bb and rrB_ = yellow kernel color
rrbb = white kernel color
True breeding red kernel x true breeding white kernel = RRBB x rrbb
F1 genotype ratio = 100% RrBb
F1 phenotype ratio = 100% red kernel color plant.
The expected phenotype of the F1 plant is 100% red kernel color.