Are there 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. The way you get tetraploids is by applying a chemical called colchicine which messes with cells as they are dividing. You add it to diploid seedlings and then some cells become tetraploid. You have to cultivate these over several generations to get enough that produce enough viable seeds with suitable traits. Watermelon plants have male flowers and female flowers.

The female flowers have a little pea-sized melon behind it. The white seeds are mealy in large quantities, irksome when mixed into watermelon recipes , and more difficult to avoid than black seeds.

And, yes, it just feels wrong to call a watermelon seedless when its seeds are right there, glimmering in the summer sun. By providing your email, you agree to the Quartz Privacy Policy. Skip to navigation Skip to content. Discover Membership. Editions Quartz. More from Quartz About Quartz. Follow Quartz. These are some of our most ambitious editorial projects. Following these steps generally produces a more than 90 percent germination rate.

High germination rate is important since seed of seedless types is quite expensive compared to seeded varieties. The standard number of chromosomes in watermelon is This is called the diploid number di meaning two, as in dissect — cut in two. With this even number, cell division is highly regular and produces pollen and egg cells with 11 chromosomes that recombine to produce seed with the usual 22 chromosomes.

Through a chemical process, the chromosome number can be doubled from 22 to 44 tetraploid, tetra meaning four. Cell division in plants with 44 chromosomes is, again, highly regular and will produce pollen and egg cells with 22 chromosomes that recombine to produce seed having 44 chromosomes. However, if pollen from a plant with 22 chromosomes is placed on a female flower of a plant with 44 chromosomes, the resulting seed will have 33 chromosomes triploid — three sets of the base number of 11 chromosomes.

This odd number does not produce or rarely produces viable pollen and eggs in the resulting seedlings. Seedless watermelon fruit will have white seed traces, but only occasionally will it have a mature, brown, hard seed.

Since the pollen of these plants is not viable, a diploid, seeded watermelon needs to be planted along with the seedless variety. The diploid will provide good pollen for the bees to move around and pollinate the flowers of the seedless variety.