Candace
Well-Known Member
An interesting article posted on one of my orchid lists this morning. http://www.kuenselonline.com/2010/modules.php?name=News&file=article&sid=16898
Interesting Virus Article
- Thread starter Candace
- Start date
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Paph_LdyMacBeth
Guest
Not cool. Not cool at all.
hardy
Well-Known Member
Ugh... A little dramatized I think. I really hope it's not that bad, and I don't think it could be that bad. Orchid viruses spreading to nursery plants that is very likely. Even phalaenopsis growers in Taiwan have to deal with it, with viruses sometimes detected in the exported plants. However for orchid viruses to "wipe out the country’s entire wild orchid species", that's unlikely I think. But it's good the article raises awareness for how important quarantine control is.
mormodes
Well-Known Member
In addition to Candace's article I think there's a Scientific American article about increased commercial orchid viruses. It appears to be more widespread than one would think. http://www.scientificamerican.com/article.cfm?id=virus-ravages-orchids
NYEric
Well-Known Member
Potentially, if mismanaged in a typical governmental fashion, the problem could be spread to wild native orchids! But let's hope not.
smartie2000
Well-Known Member
If these viruses were to spread to all wild orchids, that would not happen right away. That is if it is even possible. And if viruses could spread, logically plant pollen could potentially spread, because of exposure, and pollinate wild plants. (new wild hybrids, new 'species'...)
But there isn't really a good solution other than for nurseries to trash these plants, which is not very profitable. If we made the inspectors inspect for viruses, I suspect that importing rules would be even more strict than they already are (don't we already complain about importing limitations?). Canada limits importation of some plants due to fear of the spread of plant viruses, that could be applied to orchids, although very unlikely.
But there isn't really a good solution other than for nurseries to trash these plants, which is not very profitable. If we made the inspectors inspect for viruses, I suspect that importing rules would be even more strict than they already are (don't we already complain about importing limitations?). Canada limits importation of some plants due to fear of the spread of plant viruses, that could be applied to orchids, although very unlikely.
Candace
Well-Known Member
There are currently many people who grow their orchids outside. Even greenhouse growers don't have hermetically sealed chambers. Bugs, insects etc do cross in and out. There are of course virused orchids among these stocks of plants. And so far, no native orchid habitats have been destroyed. I'd want to see evidence of this before joining the "sky is falling" bandwagon. But, I could see how virus could become introduced and spread. It's an interesting subject, for sure.
Paphman910
Well-Known Member
I wonder how suspectible Paphs and Phrags are to these viruses in a mixed collections.
Paphman910
Paphman910
SlipperFan
Addicted
Did you see the close-up of the disease in that article? It didn't look like Cym. mosaic to me, but rather a fungus or bacteria. Anyone else?
E
Eric Muehlbauer
Guest
There's a thread on OSF about viruses. Apparently the phal imports from Taiwan are even more heavily virused than I had thought they were.
bullsie
Well-Known Member
Comming from an area that saw the loss of American Chestnuts and Elms, I can quite easily understand the fear of losing native plants to something higly contageous (a fungus in the case of Elms).
SlipperFan
Addicted
And now there is the Emerald Ash borer -- devastating the elm trees in Michigan and a couple of near-by states. And no matter how they try to contain this beetle, it is spreading.
Leo Schordje
wilted blossom
Exaggeration is as harmful to a cause as an out right lie. To paraphrase the philosopher-poet-comedian George Carlin, "That article is Bull***t and its bad for you." :evil:
The article correctly identified the mode of transmission of the virus, tools, touch and pollen. The claim that these nursery plants could endanger wild populations is completely false. Even if nearby wild orchids were pollinated by infected plants, the weakening of the individual plant in the wild would cause it to die sooner that its healthy neighbors, thus removing it as a source of wild innoculum from the local population. Only if a local vector in the wild habitat were spreading the disease significantly faster than the virus killed off the plant, only then could the virus spread in the wild. Because virused plants bloom less often, and the flowers collapse quickly, they are less likely to have their pollen picked up by insect pollinators. The spread into wild populations would naturally be self limiting.
Fungal and bacterial diseases are the type of plant disease that truly can wipe out a species, witness the American elm and the American and European chestnuts. Here a well run phytosanitary inspection program can really help, though it is not a fool proof system, and invasive pathogens can slip through undetected.
A little side note, the American Chestnut Foundation has published recently that by 2015 there should be sufficient stock of hybrid American chestnuts that are blight resistant to be released for the first wave of replacing the American Chestnuts. These hybrids are F3 to F5 with only 1/32 of the parental contribution being Chinese chestnut. The breeding program has been selecting parental stock from each generation for timber characteristics, nut flavor and oil content, in addition to disease resistance. The hybrids will be nearly identical to American chestnuts, except possibly maturing at only 75 to 100 feet in height, where the original American chestnut could reach heights of 150 feet or more. The final size won't be truly known for a couple hundred years, but that is the guess from the breeders. There is also another group working on disease resistant Amer. chestnuts using only American chestnut stock. Their results have been very limited so far. Another approach to growing American chestnuts is to deliberately infect trees when they reach about one inch in diameter with a hypo-virulent strain of the blight. The hypo-virulent blight still causes burls or cankers, and does weaken the tree, but usually the trees continue to grow, flower and produce nuts. Of interest for Dot and our many Michigan members, the first American origin strain of hypo-virulent blight was isolated from surviving century old chestnuts in north central Michigan. A lot of work was or is being done with the blight at MSU in Lansing. So there is hope our grandkids could once again go on a chestnut harvest in October, and roast them by the open fire.
The article correctly identified the mode of transmission of the virus, tools, touch and pollen. The claim that these nursery plants could endanger wild populations is completely false. Even if nearby wild orchids were pollinated by infected plants, the weakening of the individual plant in the wild would cause it to die sooner that its healthy neighbors, thus removing it as a source of wild innoculum from the local population. Only if a local vector in the wild habitat were spreading the disease significantly faster than the virus killed off the plant, only then could the virus spread in the wild. Because virused plants bloom less often, and the flowers collapse quickly, they are less likely to have their pollen picked up by insect pollinators. The spread into wild populations would naturally be self limiting.
Fungal and bacterial diseases are the type of plant disease that truly can wipe out a species, witness the American elm and the American and European chestnuts. Here a well run phytosanitary inspection program can really help, though it is not a fool proof system, and invasive pathogens can slip through undetected.
A little side note, the American Chestnut Foundation has published recently that by 2015 there should be sufficient stock of hybrid American chestnuts that are blight resistant to be released for the first wave of replacing the American Chestnuts. These hybrids are F3 to F5 with only 1/32 of the parental contribution being Chinese chestnut. The breeding program has been selecting parental stock from each generation for timber characteristics, nut flavor and oil content, in addition to disease resistance. The hybrids will be nearly identical to American chestnuts, except possibly maturing at only 75 to 100 feet in height, where the original American chestnut could reach heights of 150 feet or more. The final size won't be truly known for a couple hundred years, but that is the guess from the breeders. There is also another group working on disease resistant Amer. chestnuts using only American chestnut stock. Their results have been very limited so far. Another approach to growing American chestnuts is to deliberately infect trees when they reach about one inch in diameter with a hypo-virulent strain of the blight. The hypo-virulent blight still causes burls or cankers, and does weaken the tree, but usually the trees continue to grow, flower and produce nuts. Of interest for Dot and our many Michigan members, the first American origin strain of hypo-virulent blight was isolated from surviving century old chestnuts in north central Michigan. A lot of work was or is being done with the blight at MSU in Lansing. So there is hope our grandkids could once again go on a chestnut harvest in October, and roast them by the open fire.
likespaphs
some call me brian
is this kinda like a flu shot?
bullsie
Well-Known Member
In the English languarge, those two words can be the biggest the world has ever seen. And I sure wouldn't want to go up against them!
paphioboy
hehehe...
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Hypovirulent protection is based on the premise that getting a little disease (mild strain of the disease) is better than getting a particularly nasty strain of it. So the plant is intentionally inoculated with the mild strain. Learnt this in plant pathology class.. heheh
Leo Schordje
wilted blossom
well said Paphioboy
Yes, but it is important to recognize exaggeration when you see it. The claims that virused nursery stock will certainly cause extinction of a species is stating that the extreemly unlikely event is the guarrantteed outcome of an event. This virus claim parallels a statement like your chances of getting hit by lightning on a sunny day with a cloudless sky is a 100% certainty. Simply bogus exaggeration of a very unlikely event.
There are imaginable scenarios where both events could possibly happen, but the probability is very remote and requires special case situations.
Yes, but it is important to recognize exaggeration when you see it. The claims that virused nursery stock will certainly cause extinction of a species is stating that the extreemly unlikely event is the guarrantteed outcome of an event. This virus claim parallels a statement like your chances of getting hit by lightning on a sunny day with a cloudless sky is a 100% certainty. Simply bogus exaggeration of a very unlikely event.
There are imaginable scenarios where both events could possibly happen, but the probability is very remote and requires special case situations.
E
Eric Muehlbauer
Guest
So I decided to buy some Agdia test strips, and tested my phals...all 3 of them. Interestingly enough, the 2 that I bought on the street- typical Taiwan phals in the clear pots with NZ sphagnum- were negative. The one I bought in a store- not a big box store, but a nice plant shop with a good selection of orchids- was positive for Cymv.
chrismende
Well-Known Member
Teststrip time for me, too! My mixed collection has so many oddities on leaves that as a relative beginner I find hard to identify, that it would be prudent for me to test those areas when I find them. Agreed, folks?
SlipperFan
Addicted
Can't hurt!
