>From what (little) I know of the subject, most plant viruses are
fairly specific in their damage to a particular host *family* of
plants. Given a particular prefered host, another of that same
family of plants may also act as a host. That does not mean that
that other host plant will show any symptoms at all, merely that it
will act as a carrier until the virus is passed on to another
prefered subject. However, they definately can *NOT* infect animals
(although animals injected with plant viruses do produce anti-sera
to the virus which can then be used against the original virus).
Some viruses can also survive on other unrelated species of plants
too, so the problem is not a simple one. This is important when
trying to erradicate virus from a particular area - totally
eliminating all infected plant material may not be sufficient
since the virus may simply be waiting patiently in another species
which has not been removed. The result - re-introduce the original
plant and the disease comes back too.
As far as transmission is concerned, away from their host, many
viruses are weak and are fairly quickly destroyed by sunlight (this
causes difficulties with the use of some biological agents for
controlling some pests). Unfortunately, I don't think this applies
to TMV which is fairly robust and can have a number of different
hosts. Some viruses can only be transmitted by one specific carrier
(eg. Cocoa swollen shoot disease is only transmitted by a specific
mealy-bug - laboratory experiments rely on this vector for
propagation of the disease).
Perhaps some experiments on CP's are needed?
Regards, Adrian Arnold
arnold@bigb.win-uk.net.
>writserv@mi.net (Rand) writes
>
>> but why do think that a virus that may infect one plant will
>> infect another dissimilar?
>
<SNIP>