Why watermelons are seedless

More watermelon information can be found at the National Watermelon Promotion Board website. For more information on commercial vegetable production, contact Ron Goldy at ext. This article was published by Michigan State University Extension. Seedless watermelon — how do they do that?

Did you find this article useful? Please tell us why Submit. Learn More. Integrated Pest Management Academy. The Vegetable Beet Webcast April Seminar: Vegetables disease management using host resistance and fungicides. Related Content. Search Search. My daughter loves watermelon and I was thinking she was getting big enough to have a seed spitting contest.

But watermelon seeds seem to be vanishing. I'm used to seedless grapes but only recently became aware of this watermelon situation. Seedless watermelons have been growing in popularity since From the standpoint of a plant, the whole point of fruit is produce seeds, so I wondered what kind of hanky panky was going on to produce seedless watermelons.

Turns out that they are like mules, self-sterile hybrids and involve a lot of work. Watermelon plants are usually diploid, like us, meaning they have two sets of chromosomes, the packages of DNA with instructions for life.

Seedless watermelons are triploid. They have three sets of chromosomes. This odd number results in them being sterile and not producing seeds. The way they become triploid is by mating a diploid male with a tetraploid female. Tetraploids have four sets of chromosomes. This chemical inhibits cells division and tetraploidy is induced. The induced tetraploid watermelon plants are mostly fertile producing tetraploid progeny through their seed.

Breeders maintain these tetraploid lines in isolation plots just as they do normal, diploid watermelons. As stated above, the triploid plants are essentially sterile, since it produces defective gametes gametes are pollen or egg cells. A few fertile gametes are produced, however, but the number produced is less than 0. Since a few fertile gametes are produced, a few hard seeds can develop; whether they occur or not depends on growing conditions as well as genetics.

The development of these pips is dependent on the variety and environmental conditions. Crop Production. Did you find this helpful? It was helpful.