The potato flower must attract insects to suck the pollen within it. The flower's pollen attaches to the insect's body as it eats.
The insect moves from flower to flower nourishing itself with each flower's nectar. As it does this, it spreads one flower's pollen to the other flowers.
The insects spreading of pollen from flower to flower fertilizes the plant flower.
Once a flower has been fertilized, seed formation is on its way. A potato flower turns into a potato berry as its seedpod.
As the seedpod matures, the seed inside becomes viable and capable of growing a potato plant for the next season. Breeders take advantage of this true potato seed to create new varieties of potato, something that cannot be done with conventional seed tubers.