the fruit produced has the DNA of the new, grafted plant, not that of the sapling that's been grafted. It actually changes the DNA of the tree to that of the other tree that was "implanted" in it.
That was what I took away from Botany of Desire
There are also some that speculate the organ transplantee takes on certain aspects of the organ donor. It hasn't been proven scientifically yet, it is just a theory.
Oh, so you already knew the answer. Like I said, I was trying to reason it out, so I didn't look it up. However, I'm surprised that there is transfer of DNA to the fruit. How does that happen ... at a cellular level? That's tough to wrap my brain around, since DNA doesn't usually work that way. Does it totally alter the offspring? So, does that mean the fruit isn't always desirable to reproduce? What about the trees they graft to grow several different types of apples on the same tree ... what happens to the fruit of the original tree?