does this look like a virus?

[Aaron888]

I am about 2/3's through testing and will have to order more tests to do everything. I am definitely sick because I would say as of now I have probably tossed well over half of my collection. The silver lining is I have had zero infections in my Phrags. and my Paphs that are big enough to test zero as well. Also all of my more unusual orchids came back negative as well. I lost all but one of my Cats. and so far my Phals. are mostly turning up Positive. Any recommendations for a source of phals. that are clean? I had no idea about Phals. being bad to have virus and so I suspect either the Cat. the elderly man gave me of being the source or the Phals. (most of my phals. I picked up at big box stores because my logic being -I thought they were mericloned so would be virus free because who would bother to mericlone sick plants. I do live within driving distance of Carter and Holmes ( a little over an hour away) if that is a good source.

 

[southernbelle]

Carter and Holmes is an excellent source as they guarantee any orchids they grow against virus (but not those they get in from other vendors). Waldor is excellent as well. They will test before they ship if you ask them to, for $5. Basically, ask anyone you buy from to test before they ship. On eBay, I ask before I bid f it’s not stated in the listing. Krull-Smith, Orchids Ltd., Shogun Hawaii will as well.
Oh, and spider mites do move from plant to plant. I was at one greenhouse where some phrags had come in with them and the vendor showed me how they had spread from one bench to the next before he got on top of it. It was sort of like a wave of damage.

 

[terryros]

I am about 2/3's through testing and will have to order more tests to do everything. I am definitely sick because I would say as of now I have probably tossed well over half of my collection. The silver lining is I have had zero infections in my Phrags. and my Paphs that are big enough to test zero as well. Also all of my more unusual orchids came back negative as well. I lost all but one of my Cats. and so far my Phals. are mostly turning up Positive. Any recommendations for a source of phals. that are clean? I had no idea about Phals. being bad to have virus and so I suspect either the Cat. the elderly man gave me of being the source or the Phals. (most of my phals. I picked up at big box stores because my logic being -I thought they were mericloned so would be virus free because who would bother to mericlone sick plants. I do live within driving distance of Carter and Holmes ( a little over an hour away) if that is a good source.

Mericlones of infected plants can still be infected. If a careful, more difficult technique is used for mericloning (done by only some people) you can produce some “clean” off-spring, but I would still test for a few years. Initially clean mericlones could also become infected again during the process of growing in the commercial site if careful techniques are not used.

 

[southernbelle]

Mericlones of infected plants can still be infected. If a careful, more difficult technique is used for mericloning (done by only some people) you can produce some “clean” off-spring, but I would still test for a few years. Initially clean mericlones could also become infected again during the process of growing in the commercial site if careful techniques are not used.

The only thing that’s for sure, is nothing’s for sure…. As you point out, (only one scientist I know of) Beth Lamb in FL, has developed a process to clone the virus out of a cultivar. The process is very labor and time Intensive, using many generations of tissue culture to clone the virus out of the tissue. This is my totally layman’s explanation, but as I understand it (for what that’s worth),
after numerous generations each new piece of meristem tissue, has a lower and and lower viral load, until finally one is clean and the subsequent meristems are clean. So all future meristems are clean and won’t revert.
But, having said all of that, it’s very costly, because time consuming as each generation of meristem takes time), and so far has only been done by a couple of vendors on valuable, historic virused plants because many must be produced to make it cost effective. C. wars. ‘Firmin Lambeau’ for example. I only know of one vendor who had a clean original cultivar that he had Beth meristem. It was Cattleya wars. F.M.B. The meristems are avail on eBay. If you get a small early plant, they are reasonable. $50 or so. But a couple of years later when plants reach a better size (like now) they can get pricey. They will be gone after the ones each vendor had done are gone. And then, priceless, because the originals are not obtainable even if virused, because so few still exist.
This makes me think of those great icons of years past, who did not live to see the precious historic cultivars that they kept and nurtured even though virused, hoping for the day when viruses could be overcome. I’m thankful for the new generation of orchid growers who care about the historic plants and preserving them.
And having said all of this, Terry is right. If the commercial site (and each person who buys one) does not keep them virus free, well, it starts all over again… and so it goes.

 

[SelectOrchids]

I did a lot of virus decontamination for Phalaenopsis pot plant, so for the explanation:

- In the early days people wrongly believed that 'meristem' was the solution to decontaminate a plant from its virus. After some cultures, the plants would come up 'clean'
- Those were the days of the immunology tests on agar, then the early versions of ELISA, and even the most recent ones.

What happened is that the viral load was much lower, but not nonexistent, and below the detection level. In some massive problems, Lilium 'decontaminated and tested' started to show virus symptoms, and be positive, 1 to 2 years after field plantation.

When PCR came in the game, it was found that simple 'meristem culture' ( that technically does not exist, nearly all the technic includes at least the primordia around the meristem) was not a solution at all.

It was found that antivirals, thermotherapy etc... are required to get rid of the viruses, and it does not always work. At a point the antiviral agents used induce mutations too, so not only the plants have to be PCR tested to be virus free, but they have all to be bloomed. Then out of that, a plant that is virus free and identical to the motherplant is tissue cultured again. It is very labor intensive, and takes indeed some years to decontaminate a plant. For top quality pot plant Phalaenopsis varieties, it is worth financially, for others, it is only if there is someone to pay for virus free plants of a specific variety. That's why most growers do not care about viruses, and just sell.

The same as the urban legend that seed culture will produce virus free plants. Green capsule, never, and that's what most labs require. It is less labor intensive to sow green capsules. Dry seeds, it depends, but out of 1000-2000 seedlings, there will be a few dozens that are ORSV positive if the plant is infected. CyMV has a lower rate of positive in dry seeds, but still some here and there. That's why I never keep any virus infected plant.

I do test everything that enters, even the tiny species. There is a trick with the Agdia Immunostrips as well that is less well known. it is possible absolutely to mix samples, and test batches of 5 or more plants per test. We did a large scale testing here to see the reliability, and it is extremely reliable. At least, if the 5 are negative, 1 test is used to see it. If they are positive, back to individual testing or 3+2 then test the second round that is positive. I usually test every 6 months to a year new plants for a while as well. Virus can have a very weird pattern during the initial infection, such as a half of the Phalaenopsis that is infected, the other side is not yet positive, etc... But after 6 months, if the plant has been infected just before purchase, it will show it.

 

[terryros]

I did a lot of virus decontamination for Phalaenopsis pot plant, so for the explanation:

- In the early days people wrongly believed that 'meristem' was the solution to decontaminate a plant from its virus. After some cultures, the plants would come up 'clean'
- Those were the days of the immunology tests on agar, then the early versions of ELISA, and even the most recent ones.

What happened is that the viral load was much lower, but not nonexistent, and below the detection level. In some massive problems, Lilium 'decontaminated and tested' started to show virus symptoms, and be positive, 1 to 2 years after field plantation.

When PCR came in the game, it was found that simple 'meristem culture' ( that technically does not exist, nearly all the technic includes at least the primordia around the meristem) was not a solution at all.

It was found that antivirals, thermotherapy etc... are required to get rid of the viruses, and it does not always work. At a point the antiviral agents used induce mutations too, so not only the plants have to be PCR tested to be virus free, but they have all to be bloomed. Then out of that, a plant that is virus free and identical to the motherplant is tissue cultured again. It is very labor intensive, and takes indeed some years to decontaminate a plant. For top quality pot plant Phalaenopsis varieties, it is worth financially, for others, it is only if there is someone to pay for virus free plants of a specific variety. That's why most growers do not care about viruses, and just sell.

The same as the urban legend that seed culture will produce virus free plants. Green capsule, never, and that's what most labs require. It is less labor intensive to sow green capsules. Dry seeds, it depends, but out of 1000-2000 seedlings, there will be a few dozens that are ORSV positive if the plant is infected. CyMV has a lower rate of positive in dry seeds, but still some here and there. That's why I never keep any virus infected plant.

I do test everything that enters, even the tiny species. There is a trick with the Agdia Immunostrips as well that is less well known. it is possible absolutely to mix samples, and test batches of 5 or more plants per test. We did a large scale testing here to see the reliability, and it is extremely reliable. At least, if the 5 are negative, 1 test is used to see it. If they are positive, back to individual testing or 3+2 then test the second round that is positive. I usually test every 6 months to a year new plants for a while as well. Virus can have a very weird pattern during the initial infection, such as a half of the Phalaenopsis that is infected, the other side is not yet positive, etc... But after 6 months, if the plant has been infected just before purchase, it will show it.

Thank you very much. I have read some of your excellent results before.

 

[gonewild]

Doesn't the invitro process of many repeated cloning phases for virus removal have high risk of genetic mutation?
If so then there becomes a risk that the cleaned clone may not actually be a division of the original prized plant. Mutated clones can look identical but actually pass on different genetics when used it producing new hybrids.

 

[SelectOrchids]

Doesn't the invitro process of many repeated cloning phases for virus removal have high risk of genetic mutation?
If so then there becomes a risk that the cleaned clone may not actually be a division of the original prized plant. Mutated clones can look identical but actually pass on different genetics when used it producing new hybrids.

You are right, it depends on the lab doing the multiplication, and its protocols. But even with a 'perfect' lab, when you are using thermotherapy or antivirals, you have a risk of mutation.

I did Phalaenopsis on a very large scale, and to have mutation-free plants after 15-20 cycles needs some very specific protocols and media, including all the replates done perfectly on time. The media composition are as well very unique and you have to adjust in Phalaenopsis groups. Whites and Pink standard, the yellows soft flowers, yellow waxier flowers, harlequins, mini equestris types, etc, etc... It is not the same media or process for all when you want to make 20-50.000 plants out of one.

Actually that's poor tissue culture done by a lab that produced 100% of all the harlequins that existed, historically. But in some genera, you do have weird things, chromosome doubling is very common in Miltoniopsis if the cultures are kept a bit too warm as an example.

With a good lab, and there are not that many, small scale tissue culture is very safe including to make plants genetically identical to the motherplant, but when you reach a lot of cycles, they are perfect copies for the mass-market, and there is no guarantee ever that they are 100% accurate. They visually can be a perfect copy, the remaining is totally unknown.

 

[terryros]

Assume that I have a standard mericlone seedling from an infected plant. Or, even a seedling made using the pollen of an infected plant. The viral load is too low to be detected with commercial kits I can buy (e.g. Agdia). Can it take several years or more before the infection becomes detectable with my kit?

 

[southernbelle]

I did a lot of virus decontamination for Phalaenopsis pot plant, so for the explanation:

- In the early days people wrongly believed that 'meristem' was the solution to decontaminate a plant from its virus. After some cultures, the plants would come up 'clean'
- Those were the days of the immunology tests on agar, then the early versions of ELISA, and even the most recent ones.

What happened is that the viral load was much lower, but not nonexistent, and below the detection level. In some massive problems, Lilium 'decontaminated and tested' started to show virus symptoms, and be positive, 1 to 2 years after field plantation.

When PCR came in the game, it was found that simple 'meristem culture' ( that technically does not exist, nearly all the technic includes at least the primordia around the meristem) was not a solution at all.

It was found that antivirals, thermotherapy etc... are required to get rid of the viruses, and it does not always work. At a point the antiviral agents used induce mutations too, so not only the plants have to be PCR tested to be virus free, but they have all to be bloomed. Then out of that, a plant that is virus free and identical to the motherplant is tissue cultured again. It is very labor intensive, and takes indeed some years to decontaminate a plant. For top quality pot plant Phalaenopsis varieties, it is worth financially, for others, it is only if there is someone to pay for virus free plants of a specific variety. That's why most growers do not care about viruses, and just sell.

The same as the urban legend that seed culture will produce virus free plants. Green capsule, never, and that's what most labs require. It is less labor intensive to sow green capsules. Dry seeds, it depends, but out of 1000-2000 seedlings, there will be a few dozens that are ORSV positive if the plant is infected. CyMV has a lower rate of positive in dry seeds, but still some here and there. That's why I never keep any virus infected plant.

I do test everything that enters, even the tiny species. There is a trick with the Agdia Immunostrips as well that is less well known. it is possible absolutely to mix samples, and test batches of 5 or more plants per test. We did a large scale testing here to see the reliability, and it is extremely reliable. At least, if the 5 are negative, 1 test is used to see it. If they are positive, back to individual testing or 3+2 then test the second round that is positive. I usually test every 6 months to a year new plants for a while as well. Virus can have a very weird pattern during the initial infection, such as a half of the Phalaenopsis that is infected, the other side is not yet positive, etc... But after 6 months, if the plant has been infected just before purchase, it will show it.

I don't know for sure because I've only heard second hand, but it sounds like the process you speak of with the PCR testing of several generations of meristems is the process Beth Lamb in Florida does. She's pretty well known for her expertise. Each successive generation of tissue culture lessens the viral load until it is non-existent. Time consuming and costly. But for those historic cultivars that either don't exist virus free or have so few in existence that are virus free, certain vendors find it worth it to preserve historic plants. And if 300 meristems are ultimately produced virus free, the money can be recouped over time, especially as the plants get larger and can triple, etc. in price.

 

[southernbelle]

Assume that I have a standard mericlone seedling from an infected plant. Or, even a seedling made using the pollen of an infected plant. The viral load is too low to be detected with commercial kits I can buy (e.g. Agdia). Can it take several years or more before the infection becomes detectable with my kit?

Re a meristem yes it could show up after a few years, but not with the process of PCR testing and re-tissue culture until it is gone. We were always told dry harvesting of seeds produced virus feee seedlings because seed is sterile. If a pod was cut into, to speed up the process as in some mass production of phals, then seeds are infected. However, I saw an AOS webinar by the guy who oversees the Arboretum's orchids and he emphatically stated that the inside of a pod is contaminated if the plant is virused, so the seeds would be contaminated. He’s the only person I’ve heard say that, but it does sort of make sense. I’ve heard Brigett Uzar from Carter and Holmes say they do not use any virused plant for any type of propagation. I believe Waldor is the same. And then there is Orchid Fleck virus which was quite a problem in Taiwan and Australia. Taiwan has destroyed many thousands of plants to get rid of it as best they can. And there is no test yet for that!! The guy from the arboretum talks about it a lot. I’ve asked Agdia if they were developing a test for it and they are not but said several people have inquired about it. You’d think the Regabio tests from Taiwan would develop it but so far they’ve not.
Here is the webinar if anyone is interested. Scroll down to the one right after the May Greenhouse Chat.

https://www.aos.org/webinars-full-index

 

[Aaron888]

with the one Catt. that tested positive and the 2 phals. I am still paranoid about them so am planning on growing them in a different room from the rest of my plants and re-test again in about 6 months. My question is how long of a period until getting negative results until it would be safe that they are definitely not carrying a virus and can be returned to grow with my other plants?

 

[southernbelle]

Aaron:
Those plants will never be virus free in your collection. The virus does not ‘go away’ over time. If anything the symptoms become more pronounced in plants. If you watch the webinar, he speaks of tge virus remaining viable for decades. Unless you are willing to quarantine them forever, and even then, take extreme measures to not infect your other plants every time you work with the virused plants, cut your losses, destroy them before you spread the virus in your collection.
I’m certainly no expert on this and some of the things he said in the webinar were shocking to me. This is way above my pay-grade but I know from my experience and others whom I trust on this subject that it is nothing short of impossible to keep virused plants in any close proximity to clean plants and not spread infection. Growers who do this have completely storage sections of their greenhouses and never touch a clean plant after watering, etc virused plants. Even then, it happens. Not worth the risk unless your virused plant is of great historical significance and worth preserving for that reason. Think a C. wars. ‘Firmin Lambeau’ with fewer than a handful of clean divisions in existence today.

 

[SelectOrchids]

OFV will never be available as quick test, that's why it is so dangerous. Until recently too, there were only 1 ELISA type test, and it was not that reliable, with a lot of false negatives. It is due to the viral particle structure, etc...

The only 2 ways strangely to detect it were electron microscope, and recently PCR. Actually it was nearly extinct, but since 2-3 years there are many Oncidiae types from Thailand that carry it, and we start to see it more commonly. It is highly destructive for Cymbidium too.

 

[gonewild]

OFV will never be available as quick test, that's why it is so dangerous. Until recently too, there were only 1 ELISA type test, and it was not that reliable, with a lot of false negatives. It is due to the viral particle structure, etc...

The only 2 ways strangely to detect it were electron microscope, and recently PCR. Actually it was nearly extinct, but since 2-3 years there are many Oncidiae types from Thailand that carry it, and we start to see it more commonly. It is highly destructive for Cymbidium too.

How is OFV spread?

 

[Aaron888]

Aaron:
Those plants will never be virus free in your collection. The virus does not ‘go away’ over time. If anything the symptoms become more pronounced in plants. If you watch the webinar, he speaks of tge virus remaining viable for decades. Unless you are willing to quarantine them forever, and even then, take extreme measures to not infect your other plants every time you work with the virused plants, cut your losses, destroy them before you spread the virus in your collection.
I’m certainly no expert on this and some of the things he said in the webinar were shocking to me. This is way above my pay-grade but I know from my experience and others whom I trust on this subject that it is nothing short of impossible to keep virused plants in any close proximity to clean plants and not spread infection. Growers who do this have completely storage sections of their greenhouses and never touch a clean plant after watering, etc virused plants. Even then, it happens. Not worth the risk unless your virused plant is of great historical significance and worth preserving for that reason. Think a C. wars. ‘Firmin Lambeau’ with fewer than a handful of clean divisions in existence today.

I wasn't clear about what I was talking about - I apologize. The plants I am talking about are the ones that came up with a negative reading. I disposed of everything that tested positive but I am still worrying about the one Cat. that showed neg. and the 2 phals because I just don't see how they can be neg. when all the others were positive especially since they were newer plants - I am thinking maybe because of them not being in the collection as long as the others maybe they have not had time to show a positive results. So I am planning on retesting in 6 months to see if they still show up neg.

 

[SelectOrchids]

How is OFV spread?

That's the problem as well.

A lot through tissue culture The plants can be asymptomatic when they are young. Cymbidium usually show the first symptoms around the time they have a mature bulb or mature bulb + growth. Some infamous 'breeders' do clone their plants, discard the motherplant, and replace by young plants. They claim it is a leaf spot or thrips. There are breeding lines that are fully infected. OFV infected plant seeds as well are fully contaminated.

It spreads as well through mites, and contact. Strangely enough, infected plants can be oozing viral particles at night, we can even see water droplets in some of the chlorotic areas.

For the other viruses, it is possible to detect viral particles in the testa of the seeds in ORSV, as well as CyMV. What can happen however is that the protocorms will emerge and not be contaminated, but it is a kind of hit and miss. Some dry seeds are as well just contaminated,. That's why the best nurseries do not use virus infected parents, the risk is simply too high. I have thrown away my share of expensive plants this way too, right after purchase.

You have to start virus free at a point, then test everything that enters a nursery. Unfortunately in those days, there are more swappers than growers, buying this and that from Taiwan, Thailand, semipro hobbyists, everywhere. That's why they are not interested in offering virus-free plants, that would be way too costly.

In fact the simple and easy way to deal with viruses is to discard anything symptomatic, and test the asymptomatic plants. There are a lot of new viruses, and testing a plant fully would cost a couple hundreds dollars. Luckily things like Potyviruses show symptoms very early on, so there is no need for test. The same for CaCV and some of the Phalaenopsis Tospoviruses.

 

[gonewild]

Assuming a nursery maintains a virus free nursery, always adding new varieties to inventory and quarantining every plant they sell.
Seems like an impossible and costly task to maintain over time.
How much will that raise the retail prices of plants?

 

[SelectOrchids]

Assuming a nursery maintains a virus free nursery, always adding new varieties to inventory and quarantining every plant they sell.
Seems like an impossible and costly task to maintain over time.
How much will that raise the retail prices of plants?

That's what I do... but producing internally the plants, just adding few motherplants here and there.

If buying, testing, and selling, that would add about 10+US/plant... Countiing the virus infected batches that such a nursery would have to throw away on arrival. Viruses are not as well considered to be a defect legally, so the order has to be paid to the supplier, even if virus infected plants are sold....

 

[southernbelle]

I wasn't clear about what I was talking about - I apologize. The plants I am talking about are the ones that came up with a negative reading. I disposed of everything that tested positive but I am still worrying about the one Cat. that showed neg. and the 2 phals because I just don't see how they can be neg. when all the others were positive especially since they were newer plants - I am thinking maybe because of them not being in the collection as long as the others maybe they have not had time to show a positive results. So I am planning on retesting in 6 months to see if they still show up neg.

Ah, sorry, I see now what you meant. I gave way too much info... It is possible if they came in clean they have stayed clean since you've not had them long. Testing again in 6 mos. is reasonable. And then in a year, or when you repot. By the way, Keith Davis says to test the newest mature growth. Smithsonian says not the leaf tip, back from it. Take your sample from across as many veins in the leaf as you can, to get the right size sample (including the center rib is good). Before I learned this, I used to take the sample from the oldest leaf, figuring that it would be gone the quickest so I was not defacing the plant.