Stem Props, Mericlones, etc. - Orchid Board

weiss · #1 07-17-2006, 10:00 AM

Greetings,
Can someone explain to me the difference between stem props, mericlones, cuttings, and orchids grown from seedlings? I don't fully understand the different processes and the expected outcomes of the flowers? I would like to understand the above so I can make a better decision when purchasing plants. Thanks.

Mahon · #2 07-17-2006, 11:09 AM

Weiss,

Mericlones are plants which are the result of meristem propagation. Meristem is the central "brain" of the plant, which has all the information to make roots, leaves, flowers, pollen, and all the genetic traits... Mericloning is the same as "plant cloning". The flowers should be exactly the same as the plant it derived from.

Seed propagation is a more interesting way of propagation. With seed propagation, there would be two plants in flower involved for each pod produced from the pollen donor and the pollinated flower... so this promotes diversity in the genes. The flowers of this, depending on what kind of cross, will have different outcomes. Self crosses (x self) are usually about the same as the original plant, outcrosses combine features from the pollen donor and pod plant. Outcrossing is crosing the same species or grex, using unrelated plants.

An exception to this is self-pollination, where the pollinia touches the stamen because the lack of a rostellum in the column (or flexing pollinia which then touch the stigma, as in Holcoglossum amesianum). Self-pollination does not promote gene diversity. The flowers of these are almost always identical, but sometimes there are also mutations, which can be minor (coloration and/or shape), major (deformed plant and/or flowers), or good (nice shapes and/or colors).

Cuttings for orchids can be as simple as splitting a tuberoid or rooting a caniferous Dendrobium. This all depends on what kind of orchid it is. Most Macodes, Goodyera, and Ludisia are cuttings from other, usually larger, plants. These Jewel Orchids readily grow from simple cuttings. Some caniferous Dendrobiums can send out new shoots at any node along the cut cane. Vandaceous orchids can easily be propagated by cuttings, as long as there are plenty of roots. It may take a long time for the lower half (with no leaves) to recover and bloom. The plants should be exactly the same as the plant it derived from.

Stem props, I assume, would be the same as cuttings, stem propagation.

I hope this helps you understand the different methods of the more common types of propagation.

-PM

cb977 · #3 07-17-2006, 11:37 AM

Tindomul · #4 07-17-2006, 03:01 PM

Gosh its helped me!
Even Sue is cheering for you Mahon.
Ok are Keikies considered cuttings too?

Mahon · #5 07-17-2006, 05:05 PM

Tin,

Technically, a keikie would be a cutting if it is removed from the plant it derived off of. The more common term for cutting off a keikie or dividing a plant is 'dividing', so the resulting plant would be a 'division'... these will have the exact same characteristics as the plant it derived from.

A kiekie that is left on the plant where it occured, it is just a keikie, or as I call, a 'shoot' or even a 'new growth'.

-PM

justatypn · #6 07-18-2006, 12:10 AM

Wow Mahon, thanks for sharing, answered my questions...

weiss · #7 07-18-2006, 11:54 AM

Thanks for your quick reply, this really helps. I do have some more questions if I may? Regarding mericlones, how exactly are the parts of the orginal plant used to make new plants? What is the physical process involved? How is this done? I'd like to know what is involved and exactly who does what? Same questions for Stem Props.? Thanks for your time.

Mahon · #8 07-18-2006, 12:31 PM

Weiss,

Meristem is the composition of specialized cells which will differentiate into different features, like leaves, roots, flowers, etc. This is comparable to Brain Stem Cells, except a plant's meristem grows for its entire life span.

In the process of making mericlones, we need to first obtain the Shoot Apical Meristem, which is the apex part of the orchid shoot (a single meristem cell can make new plants). We also refer to this as an 'explant'. The explant is put into a growing medium, which may contain sucrose to initiate growth of the explant, and other hormones to induce growth and prevent mutations. Agar is then added to support the plant in the growing medium. The meristem will soon sprout new growth.

These plantlets then need to be moved in vitro containing Auxin. This will induce root growth in the explants.

The plantlets then have to be trained for outside enviroment. The humidity and light is reduced to normal for the outside growing conditions for the plant.

The plantlets eventually end up in a medium which is designed for the plantlets to grow.

-PM

weiss · #9 07-18-2006, 07:49 PM

Mahon,
Thanks to your info. I have a much better understanding of the processes involved. So now I'd like your estimate, and I understand that it is just a guess, on what % of orchid nurserys in the US have their own in house labs for mericlones and stem props? Would it be around say 20%, or more like 80%? I don't have a clue. Also, what % buy most of their phals. mainly from Taiwan or from other wholesalers? Finally, what % of hobbists would you guess do stem props? I would guess it to be very low?
Thanks again for your time and insight, it's really appreciated.

Mahon · #10 07-18-2006, 08:23 PM

Weiss,

Yes, understand that this is merely my opinionated guess... there are many levels of orchid nurseries, like wholesalers (including suppliers), specialized growers, and small scale growers... going by your easy to understand figures, I would say 80% of wholesalers would have propagation labs, 80% of specialized growers would have propagation labs, and 20% of small scale growers would have a propagation lab.

Now Phalaenopsis, I have no idea except that I knew some of the growers in Asia... I would say (out of your figures) about 20% of the total Phalaenopsis are taken into the US to sell... I would think that the wholesalers would micropropagate the plants and make a profit through their shipment...

As for orchid hobbyists... stem propagation would be dependant on what the hobbyist has to propagate... Ludisia, Goodyera, Macodes, and Anoectochilus are easily stem propagated by breaking off pieces at the nodes. Dendrobium is a harder to propagate by its nodes... Vanilla and Pseudovanilla easily propagate by cutting at least 3 or 4 nodes, where new growth will come out of the nodes. So basically, I have no idea, because stem propagation would be so common, I almost assume 98% of orchid hobbyists stem propagate...

-PM