In message , K
writes
echinosum writes
But Bramleys are not in that "most of the time" bit. Bramleys need to
be cross-pollinated by TWO different apple trees. So you need at
least
two other different apple trees in flower in the vicinity at the
same
time to get your Bramley to fruit.

Are you absolutely sure of this? I've just gone back to 3 of my
references and they all agree that the second tree is to pollinate the
pollinator, that the Bramley only needs one to pollinate it. But my
knowledge of genetics is too rusty to argue one way or the other.

Although plant reproduction can be weird, the idea the Bramley requires
pollination by two different varieties to set fruit doesn't make sense.
(Or at least I can't imagine how it would work.)

Meiosis is often messed up in triploids. This can result in a low
production of pollen, which would explain Bramley not acting as a
pollinator. One is left wondering why Bramley is seed-fertile but
pollen-sterile, but it wouldn't be the first triploid in which meiosis
works out differently in embryo sacs and pollen.

There are seedless apples, which may well not require pollination, but
Bramley doesn't seem to be one of them.
--
Stewart Robert Hinsley
http://www.malvaceae.info http://lavateraguy.blogspot.com