It would probably come close to the parent, but not true.

http://en.wikipedia.org/wiki/Pomelo

http://en.wikipedia.org/wiki/Grapefruit

thanks for info

I always hear about a seed "to come true" , but is it a rule for this

I have a fruit tree from seed , everybody told me that I will get a wild fruit and nothing close to what the fruit was , and had a big surprise to see after 3 years that the fruit is even better than the fruit he came from.
The tree is much much healthier and disease resistant...and so on.

What if you get a higher quality fruit from a pomelo seed . Am I wrong?

Yes it is possible to get a tree that produces better fruit than the parent, but is not very likely.

Some of the common citrus that do not come true from seed are Meyer lemon, Ponderosa lemon, Pomelo, Persian lime and Clementine. There are other but I forget which ones at the moment.

If anyone can make such a list and put it in front and "stiick-it" to the forum it would very helpfull

Two other varieties that do not come true from seed are Temple orange (tangor) and King mandarin.

One way to see if a variety will produce true from seed is just open the seed and see if there are more than one embryo.

Here is a list I attempted to gather some time ago from various internet sources that I believe to be authoritative. I don't believe it's 100% accurate, especially concerning kumquats.

link

I'm afraid I still don't know much about polyembrionic seeds. Somewhere I read that when the seed is polyembrionic, only one tree that came out of seed will give fruits just like mother's. Do I need to engraft that tree if I want to have quality fruits or not?

Since I red these posts to late, I already tossed the seeds in the trashcan.
But nothing to fear because I have another grapefruit in the fridge. :p

The first lime also did not contain seed so I'm hoping for the best about the other 2. My mom did bring me some clementines from the market and these were full of good shaped seeds which I have already potted in minicontainers and the next months I'll be hoping for the best!

I didn't read about 'true' plants/seeds because I'm kinda busy the last couple of days so I cannot join that topic but I will soon!

Something else that crossed my mind was this: if my seeds wood emerge as plants, do you need to treat them just as adult plants? I.e. cool winter period, a good citrus fertilizer,...?

No citrus don't need a cool winter.

If the limes you have are Tahiti limes (Bearss / Persian) they are seedless & your chances of finding a seed are slim to none.

The problem with citrus fruit on the market in Belgium is that they are often not labelled with the variety name. When one buys apples or pears, one asks for a specific variety, like Jonagold which is a very popular apple variety here.

Not so with citrus fruit. Oranges are either meant for "eating" (navels) or "juicing" (non navels). Lemons are just lemons and grapefruit are either "pink" or "yellow".