In my previous article I discussed the technique of mericloning. This article deals with some of the results achieved when the technique is applied to cymbidiums. When Morel accidentally discovered the feasibility of multiple proliferation of cymbidium tissue, he could not initially have foreseen the enormous impact that this technique would have on the genus. Although Paphiopedilum, Masdevallia, many Australian native orchids and other orchid genera cannot currently be reproduced by mericloning, Cymbidium can be multiplied with great ease and with wide-reaching consequences. The first is availability and price. Prior to mericloning, multiplication of a clone could be achieved only by division and plants of a choice clones were consequently both limited and expensive. There are many stories of considerable sums of money being paid for divisions and back-bulbs of clones such as Cymbidium Girhaween ‘Enid’, Cym. Rosanna ‘Pinkie’ and Cym. Balkis ‘Luath’. All this changed with the advent of mericloning. Suddenly a single lead from one of these plants could give rise to hundreds, even thousands, of exact replicas, leading to much faster distribution and lower prices. Cheap cymbidiums for mass distribution – too good to be true!
Theoretically, mericloning should produce exact replicas that are identical in all aspects with their parent. Commonly this is the case but variations do occur, especially where large numbers of mericlones are produced from the initial tissue, or where inferior techniques in the tissue culture process are practiced. Major variations are generally referred to as mutations and whilst occasionally a superior clone appears, these mutations are generally retrogressive. They commonly take the form of inferior shape, lower flower count and poor growth, yielding plants that are disappointing to all concerned. Where small numbers of mericlones (200 to 500) are produced from the original tissue, mutation should be rare or absent. However, where excessive numbers of mericlones are produced from the original source, or where protocorms are extracted from a flask and regenerated, or where mericlones are used as source material instead of the original plant, mutation can be quite a problem.
Sometimes it has been found that mericlones produce a lesser number of flowers than the parent. Here it is appropriate to check the source of the mericlone to determine whether it is an original mericlone, or a mericlone of a mericlone, especially one that has not yet flowered. We have had first-hand experience with our awarded Cym. Second Renaissance ‘Jenny Wren’. Our mericlones, taken from the parent plant, grow well and have two to three stems per mature bulb with 17 to 20 flowers per stem. Yet we have heard on several occasions that other clones, not derived from the original plant, have only 8 to 10 flowers per stem. We once grew a thousand plants of Cym. Arcadian Sunrise ‘Golden Fleece’, which Alvin Bryant had mericloned from his parent plant. There was a little variation in the clones, although two exhibited superior form and more pronounced lip markings than the original. Of equal interest was the nature of the lip markings when the plants flowered at different times during the year. We have flowered different plants of this clone over every month of the year and it appears that the most prominent lip markings appear in early winter, becoming less prominent as the year proceeds. We observed the same behaviour with Cym. Mallana ‘Caroline Hargraves’ and attribute it to environmental factors, rather than mutation.
Mericlones are with us forever and if they are produced properly, that is, in limited numbers from the parent tissue, then clones should be reliable replicas of the original. If you choose to purchase copies, then let the buyer beware! The original is best but if this is not available, obtain your mericlones from the grower who first flowered the orchid or from the person he chose to market it. Do not support the production of proliferations!