Virus on a Phrag

[Erythrone]

A few pictures of a Phrag Grande « Maybrook ». I bought it in spring 2009. I found it suspect at first sight.I disliked the spots and streaks on old and new growth. And the slightly distorted foliage too. But the plant was vigourous.

I only tested it last fall for virus. Positive for CymMV (Cymbidium mosaic virus).

I discarded it.

Many years ago I bought a Phrag percei with very similar spots and streaks on the leaves. I always tought it was suspect. But it died before I was able to test my plants with Agdia tests.

 

[SlipperFan]

Interesting -- I would have thought that was bacterial. Sorry about the plant -- from a distance, it looks quite healthy.

 

[NYEric]

Do you have cymbidiums!?

 

[Erythrone]

Yes, I have one Cymbidium. But it is OK.

Eric, many other genus can have CymMV. Here are some plants that were positive for Cymbidium mosaic virus in my collection :

Ascocenda Princess Mikasa
Bolleanthes Molière x Bollea violacea
Cattleya and LC (all my plants except one)
Dendrobium
Howeara
Miltonia
Phalaenopsis (15 plants.... all of my Phals, in fact)
Tolumnia (at least 50 plants... almost all my Tolumnias)
Withnerara

 

[Rick]

Do you know if the test is for live virus or titer for virus antibodies.
I hope SlipperKing has some info on this (being the "mad virologist").


If you test me for TB I show up positive (having worked with monkeys) but certified non-contagious. So I'm not in danger of being discarded.

In comparison to Hepatitus (which I am NOT positive for), individuals fluctuate on how contagious they are, but it still generally does not preclude people from leading a fairly normal life.

Despite the positive diagnosis the damage looks to me like typical scarring from mealies or scale (which probably transmit virus all over).

I seem to recall an article on virus in orchids that even suggested that new growth in an infected plant could be virus free.

So how much of a problem is virus? (Totally a general perspective question meant to spur conversation and debate).

 

[likespaphs]

perhaps Phrags are carriers but not susceptible to it?

 

[PaphMadMan]

Do you know if the test is for live virus or titer for virus antibodies.

These are ELISA tests (enzyme-linked immunoabsorbant assay). I'm not familiar with the details of the Agdia product, but ELISA tests normally supply an antibody to detect the presence of a specific antigen in the sample, probably a protein of the virus capsule in this case. It would be irrelevant if the virus in the sample was alive or dead.

 

[PaphMadMan]

I seem to recall an article on virus in orchids that even suggested that new growth in an infected plant could be virus free.

Actively growing meristems can be virus-free, but usually the new tissues formed become infected within a few days to weeks.

 

[SlipperKing]

The Cymbidium mosaic virus is called that because a cymbidium was the first plant the virus was "discovered" in. Just like most organisms first discovered, their name reflexes some part of their discovery. Of course, CMV (Cym virus) has now been discovered in many plants. Many of the old Phrag crosses show the same similar markings on their leaves. Probably positive for virus but if you know that and are careful, you should be ok

 

[Justin]

Erythrone, what was the overall rate of infection in your greenhouse/collection?

As for slippers, one thing I've wondered is how many bulldog paphs are infected, since many very old divisions are still in use for breeding. virus can be passed thru paph seed right?

 

[Erythrone]

Do you know if the test is for live virus or titer for virus antibodies.
I hope SlipperKing has some info on this (being the "mad virologist").


If you test me for TB I show up positive (having worked with monkeys) but certified non-contagious. So I'm not in danger of being discarded.

In comparison to Hepatitus (which I am NOT positive for), individuals fluctuate on how contagious they are, but it still generally does not preclude people from leading a fairly normal life.

Despite the positive diagnosis the damage looks to me like typical scarring from mealies or scale (which probably transmit virus all over).

I seem to recall an article on virus in orchids that even suggested that new growth in an infected plant could be virus free.

So how much of a problem is virus? (Totally a general perspective question meant to spur conversation and debate).

Good comments, Rick!


I think Agdia test is OK for living virus only. I can assure you that there were no scales nor mealies on the Phrag. I really know well those bugs!

I am not sure that this virus was really bad for Phrag, so maybe we can say that the plant was not suceptible... but the problem for me was that it could transmitted the disease to other plants. Most of the other plants that were positive for CymMV were not vigorous and were reluctant to bloom. My plants are tight together and I often touch them. And although there were no pests on the Phrag's leaves, my collection is not pest free.

And I had to deal with another virus too: Odontolossum Ringspot virus. Some plants had the 2 viruses.

So, although I was growing many of them for many years (some Tolumnias and Phals were with me since 20 years), I decided to be ruthless.

 

[Erythrone]

Erythrone, what was the overall rate of infection in your greenhouse/collection?

I would say that 1/4 or 1/3 of the non-slippers were infected (I only tested a few slippers). But many of them were very old plants that I bought when people were less concerned with viruses. And I am sure that I transmitted the virus myself. For a long time I thought that alcool was strong enough to kill virus. Many years ago, I was working at a garden center. Many or us liked to cut old roses in the evening. In a few weeks, hundreds of roses showed symptoms of virus on their foliage.

I now sterilize with burner or use disposable blades.

As for slippers, one thing I've wondered is how many bulldog paphs are infected, since many very old divisions are still in use for breeding. virus can be passed thru paph seed right?

I think that for many non orchids plants, embryo can be free from virus, but that it can be contaminated by the "mother plant" As far as I know, some embryos can be contaminated by virus that are on the seed coat. When the seed germinates, it can be contaminated. I supposed that it can be the same for orchids? Many other here will know more than me about it.

 

[Eric Muehlbauer]

From what I have read, paphs are pretty resistant to viruses. AFAIK, the only confirmed virused paph is King Arthur "Burgoyne".

 

[smartie2000]

interesting discussion. I generally trust my slippers for being non-virused, because infected plants seem rarer. I would guess there is a chance that a new growth can be uninfected and it can be rescued (but is it worth the time)

Yours is a plant of a clone that probably has been divided many times, increasing likelihood of infections. People here own them too!