"David (in Normandy)" wrote...
I notice there are some genetics experts on the forum. A question has gone
unanswered in my mind for a number of years because I didn't know who to
ask or where to look for the answer.

I've just grown a rhubarb plant from a cutting taken from my fathers plant
which is around 50 years old. I know my father took his as a cutting from
my grandfather. It may be possible that this too was from a cutting and so
on, hence the original "seed" based plant may be a hundred years or more
old and long since dead.
Can this process of taking cuttings of cuttings carry on indefinitely or
will the plant material eventually degrade or grow 'old' and die?

I vaguely recall that the aging process in animals is due in part to the
ends of chromosomes unravelling and not being copied correctly when cells
divide, a bit like analogue copies of copies of video tapes or audio
cassettes. And that the original undifferentiated 'stem cell' can only be
copied down around 60 generations (ie. copy of copy etc of original)
before the genetic material becomes too damaged for a viable cell to be
formed by division. I think this was also an issue regarding "Dolly the
cloned sheep" - there was speculation that she was born as old as her
mother genetically speaking because she wasn't cloned from a stem cell? I
am drawing a parallel here between animal cloning and vegetative
cuttings - is that valid?

So is there a limit to the viability of taking cuttings of cuttings of
cuttings etc? Is there any genetic 'age' associated with the plants?


Don't know much about the science of this but I have heard that normal
Bramley apples that have come from buds of buds of buds and so on off the
original do not produce the same fruit as those of the original tree which
is still alive.

--
Regards
Bob H
17mls W. of London.UK