I was talking with my mom the other day and we came upon the topic of apples trees. I mentioned I'd need more than one if I were to have them on the farm because they're slutty mutants and she just looked at me like I had three heads, so I figured I'd tell everyone about apple sex.
The branch an apple is on decides it's characteristics. Pollination decides the characteristics of the future tree.
When it comes to pollination, apples are not selective. They'll take pollen from any apple tree that's not their variety, even crab apples. Most apples are self-sterile (meaning they need a different variety to pollinate them) and it's important to note that the very few that are considered self-fruiting produce more and healthier fruit with cross pollination.
This means that any seed produced could have different parents from seeds in the same fruit let alone on the same tree.
Apple trees also have a habit of bud mutations or "sports" where one branch or even one apple is different from the rest. The mutation could be something simple like being slightly more red; or it could be something more drastic like being much larger, much sweeter, and striped. There was one apple a farmer found in 2009 that was 1/2 red and 1/2 green with a sharp line down the middle. These sorts of things occur fairly rarely but can happen on any apple tree. That means, even untouched by humans, one tree could have more than one variety growing on it's branches.
These two things is why we have the massive varieties of apples we do. They just kept cross breeding and mutating into amazingly different varieties til a human came along and decided they liked it just as it was and didn't want them to change any more.
So with all this free love and personal change how do we get to have varieties that are the same from tree to tree? Glad you asked.
It's actually rather simple. Just think Frankenstein.
When someone wants a new apple tree of a specific variety they just take a branch from a tree producing apples they like, and attach it to some roots. The actual process is kinda finicky but that's the basic premise. You clone the parent plant by attaching part of it to the roots of another.
The cut branch is called the scion and the roots are called (surprisingly) root stock. The root stock lends it's own characteristics to the growing tree such as disease resistance and most notably, height. Many people do not want 50 foot tall apple trees so they use dwarf or mini root stocks. The leaves, flowers, and fruiting characteristics are given by the scion. Putting these two together to form a new tree can be done by various types of grafting but that's enough info for it's own post.
So the next time you enjoy nibbling on one of these Franken-clones,
be happy that the mutant parents were slutty enough to provide such a wide variety.