Meiosis in Triploid organisms

[Jules19]

I've heard it's advantageous to artificially create triploid organisms in some cases when you don't want the organism to produce gametes (eg. making seedless grapes).

But I'm wondering what goes wrong in meiosis in a triploid cell? Does anyone know?
If I were to have guessed, I probably would have assumed that it worked fine, since there are more than two sets of chromosomes.

[Jules19]

?

it's weird how I post something about centromeres and I get like 10 responses, and then I post something that's slightly less excruciatingly boring and for some reason I get none.
scientists

[MrMistery]

you normally have n=7 chromosomes for example
diploid organism will have 2n=14 chromosomes. if this diploid undergoes meiosis each sperm/egg cell will have 7 chromosomes.
triploid organism will have 3n=21 chromosomes. if you undergo meiosis, how will you divide 21 chromosomes equally between 2 cells?

Now you see the problem?

[Jules19]

ahhh yes omg I feel dumb now. Thanks

[JackBean]

2MrMistery
what if the organism has e.g. 8 chromosomes as haploid? What is the problem then?

[MrMistery]

same problem but harder to explain without a drawing. I'll explain the same idea for a smaller even number, let's say n=2
Let's name the chromosomes a and b. diploid is aabb, so after meiosis gametes are ab.
Triploid is aaabbb. How do you divide. you can technically split 6 into gametes with 3 chromosomes, but they will be abnormal things like aab, abb, or stuff like that. this is an imbalance, and gametes like these usually die.