My father, A.A. Chadwick, is a collector of historical cattleyas - many of which are more than a century old. Over the years, a small number of these heirlooms have acquired a virus which is a disease that can adversely affect the flowers or foliage and is highly contagious. He quarantines these infected plants on a separate bench in his greenhouse where they can’t come in contact with the rest of the collection.
He continues to keep the distressed orchids because they are a window into the past, when the earliest fine varieties of species were being discovered or the very first hybrids were being introduced. In most cases, the blooms can still be photographed and even pollinated for future generations of pedigree cattleyas. But what he has always hoped for is to return the heirlooms to their original condition – when they were vigorous and healthy – before the virus zapped their strength and tarnished their fine attributes.
There had always been rumors of a few sophisticated hobbyists who had managed to grow a clean plant from a virused plant but the stories could never be verified. And, every so often, an article would appear in an orchid magazine about a university or government researcher who had some success but the technique was far beyond what the reach of the everyday enthusiast. Perhaps all this chatter was in the back of my father’s mind as he diligently maintained his bench of infected orchids.
In 2014, I attended an orchid conference in Florida and heard a speaker give an entire lecture on removing viruses from cattleyas. She had a very high success rate with cloning on a small scale and was looking for important historic plants for the next, bigger phase of her project. My father’s special bench was volunteered.
Cloned orchids have been the bedrock of the industry for the past half century and millions of identical plants are now being produced. The process of creating exact duplicates began in 1960, with a clever laboratory technique developed by Dr. G. S. Morel. Soon after, the French firm, Vacherot & Lecoufle, pioneered the procedure on a grand scale and mass distributed clones worldwide.
However, some mother plants were found to be difficult to clone, especially if they had a virus. It was also critical that a virus didn’t get passed on to the offspring. As a result of these complications, many of the most famous cattleyas were not cloned.
Our speaker at the conference addressed these concerns. Beth Lamb operates a small business with her husband that propagates orchids from seed and tissue culture. She relies heavily on her degrees in plant pathology and virology as well as her experience as an advisor to a large citrus producer and explains how cloning is performed:
“Orchid tissue cultures are started by dissecting a tiny growing point less than 1mm from the mother plant. This apical meristem is often free of pathogens due to the uneven distribution of virus within the mother plant. This culture may be combined with other methods such as heat treatment, cryotherapy, and chemotherapy to improve the odds of recovering clean plants.”
That’s easy for her to say. The cloning process is highly technical and requires sophisticated laboratory equipment and know how. Lamb is, no doubt, on the cutting edge.
Just last week, the very first clones of my father’s diseased plants started to bloom at our nursery. Not only do the flowers and foliage look great, but the plants all test negative for virus. My father is ecstatic.
Lamb’s work has far reaching implications for both industry and hobbyists. The rare historic cattleyas that have been relegated to a few private collections for so long may now return to the market as virus free clones – a century or more after they were first introduced. These are the plants that people have only read about and may, one day, be coming to a store near you.