Hello Orchid Growers May 2021
We hope you are all safe, dry and warm. We have had such a long intense period of rain and storms and our grounds are finally starting to dry out. Took the opportunity to escape for a few days camping at Foxbar Falls outside of Stanthorpe. Seemed a good idea to go somewhere cold and acclimatize ourselves for approaching Winter. Temperatures only went to 6 degrees whilst there but a week after our return were minus 2.7!
Many have requested some pictures of our nursery, so have included some in this Newsletter. Following is some information about Orchid Mericlones which we hope you will find of interest and benefit.
Thank you for your support
Ross and Liz
What is an Orchid Mericlone?
Mericlones are produced asexually from excised cells of an individual orchid plant in a sterile micropropagation process in a laboratory. They are essentially “mass produced divisions”. As such they should be identical replicas of the original “mother” plant from which they were produced. Generally, the flower and plant of the mericlone should be they same as the mother plant.
This process was first successful in orchids in the mid 1960’s. Prior to this, to obtain a plant of, say, Rlc. Glenn Maidment ‘Southern Cross’ was only possible by purchasing a division of the mother plant. This is slow and expensive as there are only a very small number of divisions available over time. Mericloning made it possible to produce many thousands of small plants of Rlc. Glenn Maidment ‘Southern Cross’. These where available for many more growers to grow on to flowering size and have this variety at considerably less cost.
How are Orchid Mericlones Produced?
Within the growing shoot of the orchid is a very small number of cells which are undifferentiated and as they develop some become leaves, stems or roots etc. Once they differentiate into these specific cells forming the working parts of the orchid they can not change again. These meristematic cells form the meristem contained in the growing orchid shoot. The meristem is very small (usually under 2mm in diameter). This meristematic area is excised (called an explant) and placed in sterile nutrient and hormone media which is agitated. This process ensures that the growing meristem does not differentiate into root or stem cells, but continues to make a larger body of meristematic cells called a callus. When the callus grows large enough it can be divided into 4 quarters. This process is repeated making 16, and again making 64, and again making 256…..
When enough pieces of callus have been propagated they are transferred to a solid media and the cells differentiate out to roots, stems and leaves making a new little orchid plant genetically identical to the mother plant.
There are basically three different ways orchid mericlones are produced for the orchid market.
- Meristem Culture. This is where the mericlone is produced only from the meristematic cells. It involves very specialist equipment and skill to excise only the very small meristematic area and is not used commonly in commercial orchid micropropation laboratories. It is more used in Scientific institutions for specific purposes.
- Tissue Culture. This is where the meristematic tissue is excised together with some of the surrounding tissue. It allows for excision of the explant to be done with less specialized scientific equipment, but still involves a high level of skill. It also allows for faster initial growth of the explant, speeding up propagation time.
- This is where small plantlets already in tissue culture flasks can be cut up and made to make more shoots. Time is saved because the all the slow hard work has already been done by someone else. It is a most dangerous and unethical means of propagation resulting in many mutations. In the first instance the flask may have been wrongly named!
Are all Orchid Mericlones Identical?
Within every living thing there is variability. A geneticist would say Phenotype (what you see) = Genotype (genes / genetics) + Environment (external factors). You need to accept that some mericlones flower very consistent from year to year across a wide range of growing conditions. There are others that shape, size, colour etc. can vary with temperature, light etc. There are well known mericlones of Cymbidiums, Cattleya and Dendrobium that can flower either yellow or green, white or pink, purple or red – depending on light and temperature conditions. Even though the mericlone orchids have the same genetics, many other factors affect the expression of the genes.
Following are some reasons why mericlones can vary from the mother plant, subsequent flowering or the picture you purchased it from.
- The mericlone is wrongly named and is not the same plant as the picture. Unfortunately, this is increasingly not uncommon. Best to buy from reputable sources that do their best to maintain integrity over sales.
- The mericlone has been produced by a faulty process. Not all types of orchids are easy to propagate by micropropagation. Some types like Hardcane Dendrobium or Cymbidium are relatively easy and runs of even 25,000 mericlones are possible from just one explant without problem. Others like some Cattleyas mutate if the micropropagation process is too fast and may be limited to even 100 plants before it is necessary to start again from a fresh explant. Experienced ethical laboratories produce the most consistent quality mericlones.
- Maybe it is not a mericlone. Just because an orchid has one name does not make it a mericlone. It is sad to say, but I often see hybrids depicted and / or sold as mericlones on the various forums. The hybrid Rlc. Glenn Maidment ‘Southern Cross’ x self, loses the “x self” and then becomes a mericlone! Buyer beware and seek knowledgeable vendors.
- The plant is a mericlone of a mericlone of a mericlone… The most reliable mericlones are produced from an original explant of the mother plant. In todays market there are many mericlones that are now 20,30 or 40 years old, and unlikely to have been produced from the mother plant. Genetic changes can occur over these long periods of time. As more and more orchids are sold by “brokers” and “mass marketers’ it is common to see a mericlone promoted as “new release” etc. when in fact it was first produced 40 or even more years ago!
- There are some mericlones of orchids which have received the highest of awards (FCC – First Class Certificate) eg Rlc. Eve Marie Barnett ‘Magnificent Watermelon Gold’ FCC/AOS. The award pictures depict this orchid flowering to such a standard. I purchased original mericlone flasks of this variety at high cost and never over the years flowered any of the mericlones to the FCC award photo standard. There are many orchids that have only once or occasionally flowered to the award photo picture. Of course, in marketing the orchid mericlone, it will always be the best picture used, not one of more common flowerings.
- The mericlone orchid plant is of poor health and / or diseased. The best quality flowers that you can expect and produce will be from healthy, disease free plants grown in conditions which are ideally suited to the variety of orchid. Substandard growth and culture will result in sub standard flowerings despite the genetic potential of the orchid mericlone.
Are Orchid Mericlones Virus Free?
Mericlones produced from meristem culture are virus free as the meristematic cells are virus free. Mericlones produced from Tissue Culture contain in addition to the meristematic cells, surrounding tissue cells which may contain virus. As a result, the orchid mericlones produced may all be virused. In the early days (1970 / 80’s) of orchid mericlone production mericlones were produced from mother plants of newly flowered virus free hybrids. Also they were produced largely by specialist orchid nurseries which also tested mother plants for virus before mericlone production. Nowadays the vast majority of orchids sold are from mass marketers / brokers / internet forums etc. whom may have little knowledge or interest in the virus status of the orchid mericlones. There are now many orchid mericlones produced and sold which are virused. It is important to practice virus management and control practices in your culture of orchid mericlones (these have been discussed in a previous Newsletter).
Why Grow Orchid Mericlones?
In the 1960’s and 70’s when orchid mericlones first became widely available, divisions of mother plants could be offered for thousands of dollars and in the same magazine or catalogue small mericlone plants of these could be offered for ten dollars. Mericlones made quality orchids available to more growers at considerably inexpensive cost.
You may be interested in growing only certain varieties, colours, shapes, sizes etc. of orchids. Mericlones allow you to tailor your collection to your interests, conditions and budget. They allow a higher degree of certainly than is possible with hybrid orchid plants.
Hopefully, the above information gives you the necessary information to maximize your success with purchasing and flowering orchid mericlones. Contrary to marketers who “guarantee what you see is what you get”, I think I have to say that an orchid mericlone is “An opportunity to flower a plant to a proven know standard, not a guarantee”. The rest is between you, the orchid mericlone and the God’s!