For starters, seedless watermelons are not completely seed-free. There are some small, white seeds to be found in the melon. These seeds are undeveloped and edible.
However, they are not considered GMO, but are a result of cross breeding.
In 1951, a university professor from Kyoto University used cochicine (kowl-chuh-seen) to double the number of chromosomes in one of his watermelon lines, creating a tetraploid watermelon with 4 sets of chromosomes (4N),
Breeding regular diploid (2N) and tetraploid(4N), results in triploid watermelons (3N). When this seeded fruit matures, the small, white seed coats inside contain 33 chromosomes, rendering it sterile and incapable of producing seeds.
Well, that’s not the end.
To get seedless watermelons, you have to pollinate female flowers on a triploid plant with the pollen from male flowers from a diploid plant.
And since triploid doesn’t produce seeds, you have to keep mating diploid and tetraploid to make them.
Though it was discovered in early 1950s, it started to be commercially marketed in the 1990s. This process is known as ploidy changes. Grapes, citrus fruits bananas, were all created with ploidy manipulation.
Say goodbye to watermelon seed spitting contest and welcome our new favorite seedless watermelons!
Check out our Instagram post for a visual illustration of this story!