Orchid Virus Screening
HERE is a bittersweet tale that illustrates how to use an orchid virus test kit, with an ending that underscores why everyone needs to be careful.
The photo at the right is a picture of a C. percivaliana 'Splendens' flower that was 29 days old.  This photo is not from the best angle to reveal the beautiful form of the flower, but instead, was taken to show some white spots on the dorsal sepal that had begun to develop after the flower had been open for about 10 days.  At 29 days, the light areas had intensified and the flowers now seemed to be fading faster than some of our other perci's.


The back of the flower (to the left) also showed some faint but worrisome markings, but the leaves of the plant, a 3 bulb lead division, looked perfectly healthy (see leaf photo to the right).
SO, WHAT TO DO?  This plant had been purchased in sheath less than two months previous to the photo date for $100 (plus about $25 shipping), so we were concerned, even though the markings might have resulted from shipping stress followed by high humidity.  I decided to test.

I cut the tissues to be tested from the suspected plant using a sterile (new) razor blade.  The makers of the kit I used reccomend using a section of leaf that shows symptoms, but in my case, the flowers were symptomatic.  Furthermore, the flowers were going to fall off in a week or two, anyway, whereas the leaves were few (3) and would be around for years, so I went for the flowers.  In particular, I went for the dorsal sepals, which, even though beginning to fade, were still full of sap.
I sliced the sepals into chunks (right), and placed most of the chunks in the extraction bottle (left).  The area of the sepals was greater than the recommended area of a leaf sample, but the sepals were thinner than a leaf, so I put a little extra in the bottle.
The bottle was capped and shaken vigorously for about 30 seconds in order to allow the ball bearings to bruise and crush the sample material so that the sap could be released into the buffer.
A plastic pipette was inserted into the extraction bottle and some fluid (now colored a bit pink) was drawn into the bulb.
Three drops of fluid were placed into the well of each testing device, and I waited three minutes for the test to develop.
The result?
The test was negative (only the control line, "C") for ORSV, but positive (2 lines, both "C" and the test line, "T" ) for CymMV.  Sadly, the plant was infected with Cymbidium Mosaic Virus!

NOW WHAT?

FORTUNATELY, the story has a fairly happy ending.  I picked up the phone and called the dealer who sold me the plant.  The dealer ran a large, reputable business, and I had done  a few thousand dollars worth of business with him in the past several years.  He was sorry to hear about my problem, but concerned that his clone might be infected.  He volunteered to search for a plant that he would test to make sure it wasn't infected,
and let me know if he found one.  In the meantime, he refunded the cost of my plant. 
It would have been smarter for me to have tested this plant at the time of delivery, since it had a substantial price (for me, at least), but because I tested in a timely manner and dealt with a conscientious operator, all worked out for the best.

Best of all, we didn't unwittingly pass on infected divisions to our customers!

Orchid viruses cannot be cured!   Both ORSV and CymMV can be transmitted to other plants by allowing small amounts of infected sap to enter even microscopic lesions on the leaves, stems, or roots of other plants.  This makes keeping an infected plant risky for your other orchids.

If you're a building a collection and thinking of buying a rare or expensive division,  why take a chance on buying a plant that could cost well over $100 without being sure? ALWAYS BUY FROM A REPUTABLE GREENHOUSE THAT TESTS ITS STOCK AND ask for the right to return the plant if it tests positive!  
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