North American Fruit Explorers mailing list at ibiblio

["Kieran and Donna" <redherring@tnaccess.com>]

This is a fascinating subject!   The set of books I consulted for background
on citrus breeding and the quest for hardy citrus was titled THE CITRUS
INDUSTRY.  There is a discussion in one of the set about selection of
budwood, and a photo of some variations of leaf in Washington navels.  A
survey was made of one grove of Washington navel trees, and 27 whole tree
variations were found that must have come from bud mutations.
    Because of citrus's tendency to prolonged juvenility, it is very
important, especially in grafting from a seedling tree or a "young budline"
to take budwood from high in the tree from thornless fruiting branches.
Buds from low in the tree are likely to be thornier, slower to crop and
lower yielding for years after grafting.
    In roses, you can get a more floriferous plant if you graft from high in
the plant. Taking buds from vigorous non blooming  shoots at the base of the
plant is said to produce shy blooming plants.
    I read somewhere that long lived trees deal with the problem of changing
conditions over their lifetime by producing a mosaic of bud mutations, so
that one part of an oak tree would be genetically different from other
parts, and presumably the acorns dropped from the more successful branches
would pass on the more successful mutations.  I have no idea where I read
this and have neither seen nor heard reference to this idea since, till now.
So I too would like to know more about the evidence for this kind of
mutation, and ideas on it's potential.   Donna