The closest thing to what you're talking about is grafting, but that's a specific thing that only works on certain species and I don't think can "glue" two entire halves of a tree back together, maybe just a branch at the most if you're very careful and lucky

It's why if you plant a seed from a random apple from the supermarket, you're very probably not going to get a tree that produces that apple. Most commerical fruit trees (including ones from your local garden centre) tend to have a bottom half that's hardy and resistant, and then a top half which was "glued" on that actually provides the fruit you want. The bottom half controls the genetic material in the seed, but the top half controls what the fruit will look like.

On the other hand, you can totally glue a snapped cactus back together, provided it hasn't been too long and the two halves aren't too damaged.

[–] Rivalarrival@lemmy.today 21 points 1 year ago

The bottom half controls the genetic material in the seed, but the top half controls what the fruit will look like.

Yeah, that part isn't true. The top half has the sexual organs, and controls both the fruit and the genetic content of the seed. The seed of that tree will be a genetic descendent of the top half, not the bottom half.

The problem is, as the other commenter stated, that the offspring of the tree are not likely to share the specific combination of genetic code that makes the exact apple we are looking for. If you want that exact apple, you need a clone of the original tree, not a descendant of that tree.

[–] ch00f@lemmy.world 7 points 1 year ago* (last edited 1 year ago)

Well the other bit about apple trees is that they exhibit extreme heterozygosity which means they need the genes of two trees to be combined to make viable seeds, and the genes of their offspring are chosen randomly.

So they're like people, the kids might exhibit traits of both parents, but they're not clones. Typically if you plant apple seeds, if they are fertile and sprout, the offspring will make apples that are different from both parents. In most cases, these apples aren't desirable, as there are only a few dozen apple varieties on the market against untold millions of possibilities.