Was this really tested by a specialist?
I once sent a specimen I had doubts about to a lab specializing in
plant viruses and they found nothing, even in the EM. Other people I
know did the same. With the same result.
ELISA tests are only of any use in case of a few well known viruses
on which test kits had been developed. The ELISA tests base on antibodies
directed against viral proteins. As the antibodies are very specific
(they have to be in order to make the test useful at all) these tests
are abslutely useless for the detection of any other virus.
In case of a wild collected plant one would not expect such a common
virus as TMV and therefor I would not expect any test except a
concentration of cell extracts followed by a negative staining for
electron microscopy being of any value.
If this is not done I'd suggest to forget the test and what you've
been told. If however the grower sprayed his plants with a
TMV-suspension (Nicotine rich cigarette extracts;-)) or tried
other effective methods of infecting his/her plants with virii, of
cause the ELISA might be right in detecting a common virus....
>
> Various questions wandering around my brain:
>
> Is it possible for an entire species of Nep (pick one with a
> small distribution) to be infected with a virus?
>
> Is is possible to eliminate the virus from a plant (at least
> propagate it in such a way that the virus doesn't get carried)?
> (Are virii carried with pollen? - maybe we could think of endemic
> virii almost like mitochondria)
A virus is never "good" or "bad" and in fact many virii which are
asymptomatic in one species might be seriously damaging another. The
general health state a plant is in also plays a big role.
The only way of which I know to get rid of a viral infection is a
heat treatment of a plant (just below the temparature the plant would
die....) followed by a meristem isolation (At temparatures where the
plant is sick the virus is also inhibited as its propagation depends
on cellular DNA/RNA and protein synthesis). It is assumed that in the
ideal case the very outer layer of the meristem should not yet be
infected.
However this method is more of a theoretical nature as a real
meristem culture (not a shoot-tip culture, which also frequently is
called a meristem culture) is very difficult to do and one would have
to isolate many meristems in order to have one which is alive _AND_
sterile (free of fungi and bacteria) _AND_ virus free....
It is usually only used in very valuable material.
Bye,
Andreas
Andreas Wistuba; Mudauer Ring 227; 68259 Mannheim; Germany
Phone: +49-621-705471 / +49-621-7152027
Fax: +49-621-7152028
E-Mail: andreas.wistuba@rhein-neckar.de
WWW: http://www.rhein-neckar.de/~carnivor/index.html