Answer:
Smooth kernel corn plant : wrinkled kernel corn plant 
Explanation:
Mendelian inheritance follows the laws of segregation and independent assortment. Thus, there exists neither co-dominance nor incomplete dominance.
Let the allele for smooth kernel trait of corn plants be represented by "S"
and the allele for wrinkled kernel trait of corn plants be represented by "s"
The genotype of heterozygous smooth kernel corn plants will be "Ss"
The offspring produced by crossing two heterozygous smooth kernel corn plants would be -
Ss * Ss
SS, Ss, Ss, ss
Out of four offspring , one offspring is homozygous smooth kernel corn plant
Two offspring are heterozygous smooth kernel corn plants
and the remaining last offspring is homozygous wrinkled kernel corn plant
The phenotypic ration is
Smooth kernel corn plant : wrinkled kernel corn plant 