Seedless watermelons are a triploid. These are hybrid between a tetraploid female and a diplod male. The plant has three copies of every chromosome and is unable to produce fertile gametes aka completely sterile.
Fruit formation is triggered by fertile diploid pollen (planted in the field In a 4:1 ratio). The fruit then continues to grow without embryo formation in the fruit seeds (pips).
Seedless watermelons are created by crossing a regular watermelon with 22 chromosomes with one that’s been chemically treated to have 44 chromosomes. The resulting hybrid has 33 chromosomes, making it sterile and seedless.
This is a bit misleading. You only need to treat the first generation of 2n watermelon with colchicine (which inhibits the movement of chromosomes during metaphase) to produce a 4n watermelon.
Once you have a 4n watermelon, subsequent generations do not require colchicine treatment.
TheGiantKorean@lemmy.world 4 days ago
That’s treated with a chemical to keep it from making seeds.
The_v@lemmy.world 4 days ago
Not even close.
Seedless watermelons are a triploid. These are hybrid between a tetraploid female and a diplod male. The plant has three copies of every chromosome and is unable to produce fertile gametes aka completely sterile.
Fruit formation is triggered by fertile diploid pollen (planted in the field In a 4:1 ratio). The fruit then continues to grow without embryo formation in the fruit seeds (pips).
ICastFist@programming.dev 4 days ago
So, the same applies to seedless grapes?
TheGiantKorean@lemmy.world 4 days ago
They’re often treated with hormones.
I sort of misspoke with regard to watermelons -
dondelelcaro@lemmy.world 4 days ago
This is a bit misleading. You only need to treat the first generation of 2n watermelon with colchicine (which inhibits the movement of chromosomes during metaphase) to produce a 4n watermelon. Once you have a 4n watermelon, subsequent generations do not require colchicine treatment.
Hadriscus@lemm.ee 4 days ago
Not the person you replied to but thanks. Doesn’t that contradict the meme ?
Steve@startrek.website 4 days ago
Seriously? I assumed sterile hybrid