North American Fruit Explorers mailing list at ibiblio

[Charles Paradise <machelp@attglobal.net>]

Thomas Olenio wrote:

What is the difference between grafting fruit trees and Dolly the cloned
sheep?

I believe part of Dolly's problem was premature aging, due to her cellular
clock being set from the starting point of a mature sheep.  Yet grafted
trees do not seem to suffer the same fate.

Earlier fruiting may be tied to the advanced cellular clock of the scion,
but it does not seem to shorten the lifespan of the tree.

Anyone know the reason?

Thomas:
Evidence occurs that shows that very old clonal genotypes HAVE changed
in subtle ways since the days hundreds of years ago when they were first
cloned.

Cider apples from England still exist as clonal genotypes that were propogated during the 1700's by rooting that today can NO LONGER be rooted.  Unless the English of that era possessed rooting techniques better than we do now, the conclusion would be drawn that some cider apple cultivars have changed in three centuries.

The sour cherry genotype "Montmorency" was first propogated in France in the 1500's.  Today it is STILL despite numerous efforts by governments and universities to replace it with a newer genotype, the #1 sour cherry cultivar most grown [at least in the United States].  It certainly seems that a genotype as old as Montmorency may still have a timing mechanism, however 500 years may not have been nearly enough to time it out and cause the decline of the Montmorency cultivar, unless we can detect its aging in subtle ways that have not interfered with its unsurpassed productivity or at least not enough to dislodge it as the standard sour cherry genotype.

Definition of "Genotype":

> This is the "internally coded, inheritable information" carried
> by all living organisms.
          This stored information
is used as a "blueprint" or set of instructions for building and maintaining
a
          living creature.
These instructions are found within almost all cells (the "internal" part),
they are written
          in a coded language
(the genetic code), they are copied at the time of cell division or reproduction
and
          are passed from
one generation to the next ("inheritable"). These instructions are intimately
involved
          with all aspects
of the life of a cell or an organism. They control everything from the
formation of
          protein macromolecules,
to the regulation of metabolism and synthesis.

But I think a synonym for Genotype would be the horticultural term "cultivar".  Does that make sense to everyone?

Charlie Paradise
zone 5 / Massachusetts /  where the original Macintosh genotype still is perpetuated