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?

--
David
.... Email address on website http://www.avisoft.co.uk
.... Blog at http://dlts-french-adventures.blogspot.com/

In message , "David (in
Normandy)" writes
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?


Plants don't show the same distinction between soma and germ-line that
animals do - just about any plant cell, in the right circumstances (e.g.
tissue culture) can give rise to a new plant. In particular it is
possible to propagate plants from sports in a way that isn't true for
animals. (Imagine producing a new colour break of cat from a hair
follicle.)

In principle plant clones can live for a very long time - see Wollemia,
some tree/shrub in Tasmania (the name escapes my recollection), Opuntia
clonal microspecies in the US South West, aspens elsewhere in the US.
However clones do have a tendency to "age". I don't think it's due to a
lack of telomerase function (I don't know about the topic, but I suspect
that plant cells express telomerase). One known cause of "aging" is the
build up of virus infections - this can be reversed by passing the clone
through tissue culture. Another is the build up of detrimental
mutations, tho' this acts on a longer timescale.
--
Stewart Robert Hinsley

"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

In article ,
"David \(in Normandy\)" writes:
|
| 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.

Well, there is only one person who might count as an expert on such
matters - and I am not that person!

| 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, ....

That was the theory, but it isn't quite that simple. Research is
continuing.

| 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?

Yes and no. It appears that the higher plants are MUCH more complex
than animals in this sort of area, and virtually everything that is
discovered turns out to be a partial truth.

To a first approximation, plants reset their 'clock' when propagated
vegetatively - see Rackham "Trees and Woodland in the British Landscape"
for some interesting remarks on coppicing and pollarding. But this is
not entirely so, because "bush ivy" preserves the growth habit of the
flower shoots and some plants flower younger if cuttings are taken from
older plants.

Most of the causes of degeneration are infection by viruses, but it is
also possible that plant cells do age - though much less so than animal
ones. Don't hold your breath for a conclusive answer, as this is likely
to remain a research topic for the forseeable future.


Regards,
Nick Maclaren.

In message , Stewart Robert Hinsley
writes
some tree/shrub in Tasmania (the name escapes my recollection),

The name has resurfaced from my memory - it's King's Lomatia (Lomatia
tasmanica), which is, from carbon dating, at least 43,600 years old.

Come to think of the matter, some of the banana clones might be pretty
old.
--
Stewart Robert Hinsley

Thank you for the replies everyone. It seems plant genetics are somewhat
different to that of animals. In my next birth I'm coming back as a
botanist - plants are absolutely fascinating. Speaking of which, I've just
seen some trees on a TV documentary about Madagascar - really stunning, I
don't know what they were called but they had really wide, tall, straight
trunks but with only a few small puny branches near the top - they almost
looked liked caricatures. They all looked similar, so I don't think they
were diseased in any way, just very odd looking. Fascinating.
--
David
.... Email address on website http://www.avisoft.co.uk
.... Blog at http://dlts-french-adventures.blogspot.com/

In article ,
"David \(in Normandy\)" writes:
| Thank you for the replies everyone. It seems plant genetics are somewhat
| different to that of animals. In my next birth I'm coming back as a
| botanist - plants are absolutely fascinating.

There are several regular posters here who can relate to that :-)

| Speaking of which, I've just
| seen some trees on a TV documentary about Madagascar - really stunning, I
| don't know what they were called but they had really wide, tall, straight
| trunks but with only a few small puny branches near the top - they almost
| looked liked caricatures. They all looked similar, so I don't think they
| were diseased in any way, just very odd looking. Fascinating.

Dunno about Madagascar, but look up baobab on the net.


Regards,
Nick Maclaren.

Dunno about Madagascar, but look up baobab on the net.
Nick Maclaren.

Spot on Nick! I Googled for "Boabob Madagascar" and found lots of images of
them.
This one is pretty good, there are people underneath so it gives some idea
of the scale and how huge they a

http://www.lacetans.org/gns/baobab_morondava.jpg

Thanks.
--
David
.... Email address on website http://www.avisoft.co.uk
.... Blog at http://dlts-french-adventures.blogspot.com/

In message , Nick Maclaren
writes

In article ,
"David \(in Normandy\)" writes:
| Thank you for the replies everyone. It seems plant genetics are somewhat
| different to that of animals. In my next birth I'm coming back as a
| botanist - plants are absolutely fascinating.

There are several regular posters here who can relate to that :-)

| Speaking of which, I've just
| seen some trees on a TV documentary about Madagascar - really stunning, I
| don't know what they were called but they had really wide, tall, straight
| trunks but with only a few small puny branches near the top - they almost
| looked liked caricatures. They all looked similar, so I don't think they
| were diseased in any way, just very odd looking. Fascinating.

Dunno about Madagascar, but look up baobab on the net.


Regards,
Nick Maclaren.

Six of the world's 8 species of Adansonia (Baobab) are endemic to
Madagascar.
--
Stewart Robert Hinsley
http://www.malvaceae.info/Genera/Adansonia/gallery.html