This came up when I gave a talk on HVX to our Master Gardener group. A comment was made (by someone whom I know to be knowledgable about hostas and HVX) that his understanding is that the TC process itself destroys HVX. I said I didn't know if that is true or not. I'd like to make a correction at the next meeting. . . what do you say, Chris?
Of course, even that is true, a TC produced hosta could get HVX through other means, so the "TC" label doesn't "guarantee" an HVX-free plant.
Chris: Does HVX survive TC process?
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Chris_W
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Hi Arlene,
I've heard this too, and included it as part of the "myths" section of my DVD.
First, I've read in a couple references that some viruses may not be present in the new buds or might be in very low concentration. This could make it possible to use tissue culture to try and clean up a plant that is virused, but only if the virus was not present in the tissue used to start the culture. However, this may not be true of all viruses, and may not be true in all cases, and may not work all the time.
It is a big stretch to say that the TC process destroys virus since I am certain that is false. It seems that it may simply be possible to isolate some tissue that just wasn't infected yet.
Extensive testing would need to be done to insure you got a virus free culture, but instead it is easier to just test the stock plant before it is propagated. I am pretty sure the major labs are testing new stock plants to make sure they are virus free. If TC got rid of virus, then why would they bother to do the initial testing?
We have also seen some cases of apparent TC plants being infected. Sure, it may have been contamination at some point in the process of getting it to a sellable liner, but it also may have been from infected stock at the beginning.
And finally there is a reported case where an infected, named plant was put into culture and came out missing its mottled color. However, after a couple years the mottling came out in the babies. So the TC process may have reduced the virus concentration so low that it could have tested negative and showed now symptoms, but then showed up later as the virus multiplied.
So no, I do not believe that the TC process automatically insures virus free plant stock.
I've heard this too, and included it as part of the "myths" section of my DVD.
First, I've read in a couple references that some viruses may not be present in the new buds or might be in very low concentration. This could make it possible to use tissue culture to try and clean up a plant that is virused, but only if the virus was not present in the tissue used to start the culture. However, this may not be true of all viruses, and may not be true in all cases, and may not work all the time.
It is a big stretch to say that the TC process destroys virus since I am certain that is false. It seems that it may simply be possible to isolate some tissue that just wasn't infected yet.
Extensive testing would need to be done to insure you got a virus free culture, but instead it is easier to just test the stock plant before it is propagated. I am pretty sure the major labs are testing new stock plants to make sure they are virus free. If TC got rid of virus, then why would they bother to do the initial testing?
We have also seen some cases of apparent TC plants being infected. Sure, it may have been contamination at some point in the process of getting it to a sellable liner, but it also may have been from infected stock at the beginning.
And finally there is a reported case where an infected, named plant was put into culture and came out missing its mottled color. However, after a couple years the mottling came out in the babies. So the TC process may have reduced the virus concentration so low that it could have tested negative and showed now symptoms, but then showed up later as the virus multiplied.
So no, I do not believe that the TC process automatically insures virus free plant stock.
