In another (non-gardening) forum there was a comment regarding a
possibly-diseased plant, and the potential for genetic damage as a possible
contraindication to using said plant for cuttings:

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"It really sounds like a fungal infection. You could try an anti-fungal
compound, but it's probably best to make a new cutting from the
healthy material and discard the diseased part of the plant."

"There is a possibility that the disease has affected the genetic make
up of your plant which could mean that the plant (and clones made from
it) will grow slowly forever more. You might want to consider throwing
your diseased plant away and start again with healthy cuttings."
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When the claim that "disease has affected the genetic makeup of the plant" was
questioned, this was the reply:


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"The fact that plants will mutate in order to cope with stress is well known."
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....and this reference was cited:


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http://people.cs.vt.edu/~ramakris/pa...resso-Pine.pdf

"The ability of a plant to protect itself against environmental stress
is essential to its survival [Alscher et°al., 1997]. Acclimation of
plants to extreme environmental conditions or to rapid changes in
growth conditions requires a global cellular response and changes in
the expression of many genes. Exposure to extremes of light intensity
and temperature, drought, and some herbicides can cause the downstream
formation of reactive oxygen species (ROS). ROS may be present in the
form of superoxide (O2—), hydrogen peroxide
(H2O2), or the hydroxyl ion (OH—). ROS, especially OH—, are toxic
because they can oxidize any macromolecule in the cell
[Scandalios°(ed.), 1997]. This potential threat to cellular function
can cause protein unfolding, the inactivation of enzymes, DNA damage,
mutation, lipid peroxidation, and consequent disruption of cell
membrane function.
--------------------


Since then, I've been pondering this, and searching for further references
without much success. What I'm wondering in particular is how one judges when a
stock plant is so unhealthy as to make propagating from it a bad idea because
of the possibility that mutations have occurred which would cause the clones to
grow poorly.

Obviously propagating from healthy plants is the best course of action; but I'm
interested in this from a theoretical point of view as well, as I hadn't been
aware that clones could be affected in this way.


Does anyone have comments or links to references on this subject? or is there a
better newsgroup in which to ask this?

Thanks!
Bill