Virus positive plants, Agdia Immunostrip.

[DavidCampen]

Here are some plants that test positive for virus and of an Agdia Immunostrip showing a positive result for Cymbidium Mosaic Virus.

The large Phalenopsis, Phal. schilleriana, tests postive for CymMV. The other 2 plants, a Phal violacea and a Blc. test positive for Odontoglossum Ringspot Virus.

[NYCorchidman]

Does Agdia only test for those two viruses?? just curious as there are so many more viruses that affect orchids.

[DavidCampen]

The Agida Immunostrips that I am using test only for ORSV and CymMV.

According to Critter Creek:
"... some 40 odd (viruses) have been shown to cause disease in orchids, and of these, at this time, only 3 seem to be of major importance, Cymbidium Mosaic Virus (CymMV), Odontoglossum Ringspot Virus (ORSV) and to a considerably lesser degree Bean Yellow Mosaic Virus (BYMV) mainly in Masdevallias. "

You can get tests for others if you want to spend the money.

Here is another Agdia Immunostrip photo. The strip on the left shows negative test from a bit of Aerangis articulata leaf. For the test strip on the right I combined root tips from my virused Phal. schilleriana and Blc. Pamela Finney to get a strip showing positive for both ORSV and CymMV.

[NYCorchidman]

Does this same company provide service for testing other viruses?

I hear viruses are very common with all these mass produced mericlones and divisions alike.
Unless plants show terrible signs (in which case I will chuck them), I decided to just keep as long as they grow and flower nicely.

[DavidCampen]

Both Agdia and Critter Creek provide testing services.
Critter Creek Laboratory
How To Submit Samples

These are the Agdia test strips that I am using:
https://orders.agdia.com/InventoryD....ribute_Size=25

Agdia also sells ELISA test kits:
https://orders.agdia.com/homepage.asp

[DavidCampen]

The Agdia Immunostrips are backordered for about 5 weeks. I have left my order standing but the Critter Creek Laboratories testing service is about the same cost.

[Cym Ladye]

David,

The two Agdia strips shown on your first post both appear to show the same virus, which I believe is ORSV on the lowest line. The second post showing both viruses on the same strip is most illustrative of the problem.

There is a back order on the Agdia strips because on lots 003 and 004 too many false positives were occurring. They have stopped distributing these lots and are manufacturing new lots. If you ordered directly from them and received one of these lots, you probably have already been notified.

CL

[DavidCampen]

Thanks for the info about the problem lots. I will check the lot number on my vial tonight but I established an account with Agdia and ordered directly from them so I expect that I would have been notified if I had one of those problem lots.

I had tested more than a dozen plants from other vendors with no positives before I tested the 5 plants from this one vendor and got positives on 3 out of the 5 plants.

Actually CymMV is the bottom most line with ORSV showing between the CymMV and Control lines:
https://orders.agdia.com/Documents/m250.pdf

In my first post with photos, both Immunostrip photos are of the same test. One was just a closer image than the other.

In the second set of photos the test showing positive for both viruses was a retest of the Phal schilleriana and Blc. Pamela Finney using plant material combined from both.

The 3 plants went into the trash last night.

[goodgollymissmolly]

Two points...first the notification of false positives on Agdia strips applies only to the testing of plants in genus Cymbidium. It specifically says that the only failures are false positives and that it does not occur on other genera.

Second..there is an article in the second quarter 2012 Journal of the International Phalaenopsis Alliance written by Erin M. Wood, Graduate Research Assistant, and JE Polston, Professor, Dept of Plant Pathology, University of Florida that addresses plant viruses. You can get much more comfortable with testing just for CymMV and ORSV by reading this article. The conclusion is that these are far away the most common and the most transmittable viruses. The 25 or so other viruses known in Phals are not so damaging and many don't even spread in the infected plant much less to other plants.

Notice I did not say these are not important just for a vatiety of reasons testing for them is not that critical. If you can get a copy of this article it is well worth your time.

[lepetitmartien]

One question I have on the strips in general, is that we don't have the basic information on the test:
- are there false positive/negative
- their proportions
- the general viability of the test

It's just like ELISA or you vaccines, they are not failsafe, and to make decisions on it means we have to really know how good they are and their known issues.

It's not an issue I have with Agdia in peculiar, other manufacturers don't have these informations available. And they should.

We take decisions to eventually discard a plant on this, nurseries can destroy plants too at a cost, it must be informed.

(note it's not anti-tests or vaccines, I just like to have the datasheet of things I use)