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Trillium Enthusiast Discussion List (and other Woodland pl= Trillium Enthusiast Discussion List (and other Woodland pl=
Thu Jul 8 00:00:02 CEST 2004


ants)"  <TRILLIUM-L at NIC.SURFNET.NL> <TRILLIUM-L at NIC.SURFNET.NL>
Sender: "Trillium Enthusiast Discussion List (and other Woodland pl=
From: Carl Denton <trilliums at TRILLIUMS.PLUS.COM>
Subject: Re: potyvirus?
In-Reply-To: <TRILLIUM-L%2004070701292265 at NIC.SURFNET.NL>
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-----Original Message-----
From: Trillium Enthusiast Discussion List (and other Woodland plants)
[mailto:TRILLIUM-L at NIC.SURFNET.NL]On Behalf Of John Lonsdale
Hello Carl,

>I think this came up in discussion last year, and I'd be interested to k=now
if you've made progress regarding correlating cause and effect. Any
questions about expression of potyvirus-induced disease in different host=s
are only applicable if you have shown conclusively that the virus causes =the
disease you observe, i.e. Koch's postulates have been met.  <

Hi John
Certainly this year and last year no evidence of fungal disease or bacter=ial
disease was found by the Central Science Laboratory of Defra in my diseas=ed
plants.
Koch's postulates have not been met as I have not the equipment or knowle=dge
to do the necessary tests myself or the money to have them done by a priv=ate
lab.

>It wouldn't
surprise me if you found potyvirus in most trilliums you looked at but th=e
effects of infection are silent, in which case something else is causing
your problems.  Have you done any more experiments to show that the virus=is
the definitive causative agent of the symptoms/disease?  Is there a
correlation between viral load and disease severity?<
Obviously with positive results in some of my 'healthy' trillium species =the
effects of infection are 'silent' but maybe later will cause disease if s=ome
other 'triggering' mechanism starts.
So far I have not been informed of viral load appart from 1 species which
had 'very few particles seen' and was not showing any signs of disease . =Its
neighbour which was loaded with potyvirus showed no disease either.
Defra are attempting to identify this potyvirus further by using a new
molecular approach but this will take some time.  In the meantime I am ju=st
watching and logging the disease to see how it progresses through the
collection.
Yours
Carl
Leeds  Yorkshire  England  Z 8
www.trilliums.co.uk
carl at trilliums.co.uk

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