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Old 03-31-2013, 09:07 AM
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Some useful information from a scientist:

These are replies from Aaron Hicks concerning my Phal. Equelacea that seems to have a nasty virus.
This is the plant in question:


P. Equalacea by Jacknet1, on Flickr


P. Equalacea by Jacknet1, on Flickr

At the bottom you will see his reply giving me permission to post his responses to the forum.
> Thank you so much for your responses. I belong to a few orchid forums and
> based on pics they had of viruses I thought mine was the same.


Diagnosis of virus by comparison with images is fraught with peril. Some of the more common pathogens (primarily odontoglossum ringspot virus) are characteristic of infection, while others are much more vague- such as the spots- and these symptoms overlap with a myriad of bacterial, fungal, and cultural (environmental) issues.
> I know it's really hard to tell without doing a Agdia test strip on them.
Even then, the strips only test for what is being sought after- and only a handful of viruses may be economically identified in this fashion. There are questions about whether other viruses may be present- particularly in mass-market phalaeonpsis- that are carried through in the tissue culture process and subsequent common culture. Foamites and vectors abound. Curious symptoms like phals simply "collapsing" have been attributed to INSV (impatiens necrotic spot virus) and TSWV (tomato spotted wilt virus). Tospoviruses are not to be dealt with lightly.
Interestingly, one of the more useful tools in the toolbox is the largely-forgotten indicator plant, in which a small quantity of sap from the plant to be tested is placed on a scarified leaf of a host plant that is susceptible to a broad array of viruses (preferably one that does not commit to systemic infection). However, many excellent indicator plants have been specifically bred in recent decades to reduce viral susceptibility, so susceptible cultivars must be found. I've found three that are useful, but the seeds are hard to find.
Is there any flower break?
> All the leaves (5) on this plant look like this and worse.
> Even the little baby leaf if you look close has a small chunk out of the tip of it.

Almost certainly this is physical damage from handling, or possibly predation (snails, slugs- a common problem to orchids, and sphagnum moss does nothing to help the problem).
The old-time growers would often have a sub-greenhouse filled with virused plants, many of which showed no signs or symptoms at all- particularly when not in flower. They were maintained for breeding purposes as the consensus (right or wrong) was that viruses were not transmitted in this fashion. Unfortunately, with hundreds of orchid genera, a dozen or so viruses, and tens of permutations as to how fruits may be produced, harvested, and processed, there is no one single answer as to whether any of these methods are consistently capable of yielding clean seedlings.
Worst case scenario, isolate the plant and grow it out; make sure no water gets on the leaves, and ensure it gets treated well. If the new growths come out clean, perhaps it was something attributable to culture. If there's no flower break, consider yourself fortunate. Run a handful of Agdia strips (it seems Agdia only sells ELISA for CyMV- an expensive proposition) or send it out to a testing service such as Critter Creek.
Critter Creek Laboratory
In case anyone is wondering, aside from the usuals (CyMV, ORSV/TbMV, BYMV), susceptibilities to turnip mosaic potyvirus, orchid fleck rhabdovirus, dendrobium mosaic potyvirus, Cymbidium ringspot tombusvirus, dendrobium vein necrosis closterovirus, habenaria mosaic potyvirus, and vanilla mosaic potyvirus have been documented in the peer-reviewed literature. Similarly, the Florida Department of Agriculture has documented both INSV and TSWV (as noted above) as being found in phalaenopsis.

http://www.freshfromflorida.com/pi/e...circ/pp406.pdf
Aaaaaand dendrobiums.

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And CaCV (capsicum chlorosis virus) from phalaenopsis:

www.insectscience.org/10.166/abstract106.html

My friends in the mass-market industry suggest there are many viruses pandemic to the trade; it is possible we are selecting for attenuated strains that are asymptomatic under the excellent conditions provided in mass-market greenhouses, and may manifest only when stressed.
Scanning electron microscopy (SEM), although useful, is hit-or-miss. Bob Wellenstein (doctorate in virology who happened to run Antec, one of the largest vendors of paphiopedilums in the country) commented to me once that he had sought viruses from infected (tested) plant tissues, and was often unable to detect any virus particles by SEM.
-AJHicks Chandler, AZ

I found some more pictures to give a better history of this plant.
1) The first is of the bloom when I first got the plant in Dec. '12
2) This is the plant and you can see it looks to me it came home with these markings already on it. This shows my inexperience in buying orchids.
3) This is the month after the two blooms came out and the spikes have already blasted and died off.
When you talk of flower break are you talking about disruptions in the color patterns?



Phal. Equelacea (6) by Jacknet1, on Flickr


Phal. Equelacea (4) by Jacknet1, on Flickr

As for the indicator plants used:

Datura stramonium (jimson weed) is good, but the plants grow very large. It smells bad, and you don't want to grow it with kids or pets around because of its toxic properties, which include delirium and other nasty effects. Seeds are usually available on eBay.

Chenopodium species (particularly C. quinoa) may be useful as an indicator plant. Seeds may be available on eBay.

Nicotiana glutinosa is probably the best indicator plant for TbMV (which may include ORSV) as it will not allow systemic infection, as per Gildow at Penn State. N. tabacum cv Samsun NN apparently performs just as well in this role. However, the cultivar Samsun itself is susceptible to systemic infection, as is N. clevelandii (just in case anyone reading this wants a plant capable of becoming a dreadful source of TbMV in the greenhouse). Seeds of nicotiana are readily available from JL Hudson, Seedsman:

J. L. Hudson, Seedsman

His seeds list is fascinating, and the section on nicotiana is of particular interest.

Seedlist N

Indicator plants are almost a lost art; I believe there's a good section on how to use them in Rebecca Tyson Northen's "Home Orchid Growing," third edition (also fourth edition, which is just a reprint of third edition).
> When you talk of flower break are you talking about disruptions in the
> color patterns?

That is correct. Again, flowers are susceptible to cultural and environmental factors that may mimic virus infection, so some caution is called for. Sometimes the symptoms may be overt:

Link Edited.. taken from another forum

The American Orchid Society produced an excellent handbook on pests and diseases of orchids; the virus section is quite illuminating. I note the most recent edition is 2008. Pricey. Maybe Bookfinder.com has a less expensive one.

Orchid Viruses

Amazon.com: Orchid Pests and Diseases: American Orchid Societyguide. (9780923096137): Books

Aaron - This is great stuff. Obviously you were considerate enough to take the time to write all this and help a struggling novice understand the situation with viruses in the orchid world.
May I copy this to my orchid forums?
Aaron J. Hicks ahicks51@cox.net via lists.umn.edu: “Of course”.
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Old 03-31-2013, 10:12 AM
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This is really interesting and useful information!
Thank you for posting it, and thanks also to Dr. Hicks!
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Old 03-31-2013, 11:10 AM
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Newbud do you think your Phal has a virus? Are you going to get the Agdia tests or send it to Critter Creek? Or are you going to toss the plant because you think it has a virus?

Your bloom does not show a color break virus although a test could prove you do have that virus. You will know a color break when you see it. I've only seen it on one Catt but a couple other Catts with virus never did show it on the blooms. I've never had a color break on any Phal that tested positive.

Brooke

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Old 03-31-2013, 01:41 PM
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Thanks for sharing, newbud!

I've never had a plant exhibit color break before, though I've seen some pretty horrid things on some of my plants' leaves. They affected plants were all cheap mass-produced mericlones so I just pitched them.

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Old 03-31-2013, 01:52 PM
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Quote:
Originally Posted by Brooke View Post
Newbud do you think your Phal has a virus? Are you going to get the Agdia tests or send it to Critter Creek? Or are you going to toss the plant because you think it has a virus?

Your bloom does not show a color break virus although a test could prove you do have that virus. You will know a color break when you see it. I've only seen it on one Catt but a couple other Catts with virus never did show it on the blooms. I've never had a color break on any Phal that tested positive.

Brooke
Hi Brooke - Some of the other suggestions I got off the TC and hometissueculture user-net was to keep it isolated and just watch it, unless I want to spend the money to have it tested, which I don't. I just ordered a home tissue culture kit from Carol Stiff so I may still end up trying to save it by cloning it if it is in fact infected. Only time will tell. Thanks for your comments.
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Old 03-31-2013, 06:06 PM
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Quote:
Originally Posted by newbud View Post
I just ordered a home tissue culture kit from Carol Stiff so I may still end up trying to save it by cloning it if it is in fact infected. Only time will tell. Thanks for your comments.
Won't cloning carry any virus forward to the new plants? I thought reproduction by seed is safe, but not by cloning. I could be wrong.
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Old 04-01-2013, 07:37 AM
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Quote:
Originally Posted by newbud View Post
Hi Brooke - Some of the other suggestions I got off the TC and hometissueculture user-net was to keep it isolated and just watch it, unless I want to spend the money to have it tested, which I don't. I just ordered a home tissue culture kit from Carol Stiff so I may still end up trying to save it by cloning it if it is in fact infected. Only time will tell. Thanks for your comments.
I think Mr. Hicks was very generous with his time to give you such a lengthy explanation with the problem of virus in orchids and also virus in other plants. I am a little puzzled why you would ask him for his knowledge, put his answer and the pictures of your Phal on the forum and then not take any action to determine if your Phal has a virus.

You can spend $5 and get an Agdia strip and test for the two most frequent viruses in Phals. For a little more money you can send it to the lab and have it tested for every other virus known to man. Or you can toss it in the trash and eliminate it so you won't fear it possibly transferring a virus to the rest of your collection.

I assume your home tissue culture kit is to try and do a stem prop. Stem props on short stems aren't very successful even for the pros. There are not enough nodes to ensure a good outcome.

If your Phal is infected, you will end up with all seedlings infected.

Brooke
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Old 04-02-2013, 03:55 AM
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research in the 60/70's indicated that mericloning orchids could eliminate virus. This was trialled and tested to success.
I suppose it depends on where the mericlone sample is taken from and how good the sterilisation of tools etc is.

Not sure if that was for all virus's or just the big 3.
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Old 04-02-2013, 05:08 AM
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You're both right and not right. Because viruses often spread into new growth slowly, it is sometimes possible to obtain a virus free tip from the apical meristem in order to clone virus free plants. North Carolina State U does this every year to supply farmers with virus free sweet potato plants. Otherwise, sweet potatoes would not be an agricultural crop.

The key to this that not all plants and/or viruses can be done in this manner. More importantly, the process must be especially intended and run to achieve the desired result. This is not your normal mericlone process resulting in some serendipity. I have no knowledge of any such information regarding orchids or any efforts in regard to horticultural crops in general.
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Old 04-02-2013, 09:31 AM
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Thanks for the info JLu.
From what I have read, it is possible to eliminate virus in orchids by mericloning, although I agree with you that surely there must be some residual in the new growths and there would be a fair bit of testing involved to be certain. That would also depend on the nature of each virus that is possible.

Having said that, mericloning has been done on virtually every part of an orchid, and no doubt some would produce less chances of carrying virus's.

Examples of where mericloning has been successful - leaf tip, root tips, vegetative shoots, old dormant eyes, lateral buds, flower stalk, and tissue culture to name a few. Each genera has a different ideal method also and virtually every genera has had cloning done to degrees of success.

So many possiblities, and in a hobby environment, only a wonder that virus's have not been eliminated. - I dream to see that world.
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Old 04-02-2013, 10:27 AM
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Is there any info on how to use the indicator plants. This roused my curiosity.
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