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.