When I started pollinating Cymbidium orchids, it was very difficult to get much information, except from orchid clubs, or difficut-to-find books. This small set of pages may help others to start out on the fascinating hobby of pollinating orchids and growing new varieties from seed.
What you need to start this short course
The two Cymbidiums should preferably both be diploid (normal wild-type 2n plants, genetically having two copies of n=20 different kinds of chromosomes in the nucleus of each cell), or both tetraploid (4n, having four copies of each kind of chromosome). If you try to cross a triploid (3n) with anything, the result may well be no viable seeds. When you have successfully set some pods by all means try, but expect some disappointment.
- A sharp Stanley knife, wood carving tool, or scalpel
- A pack of toothpicks (wood or plastic)
- Tweezers (forceps) may be handy [optional]
- Two Cymbidium orchids in flower (essential, see below)
- Perhaps some magnifying glasses - try diopter 3 reading glasses available in pharmacies [optional]
- A biggish sheet of white paper to work on [optional]
To explain what this means, when plants produce eggs and pollen, the normal number of chromosomes (DNA packages) in the nucleus of each cell (2n) is doubled (4n) and then halved twice in a pairing process, so what's in an egg or a pollen grain has only n chromosomes (called haploid). When fertilization takes place the chromosomes in the egg and pollen merge, so
A 3n plant's chromosomes can't pair up to be correctly halved, so its eggs and pollen are usually a mess and sterile. Genetic copying mistakes take place sometimes, which is how 4n plants occur and how a rare 3n cross works. We breed 4n plants because their flowers are often bigger and the plants healthier. Plants also contain DNA in their mitochondria (sugar energy factories) and chloroplasts (solar energy factories), but these are inherited solely from the pod parent (female), without sex.
- n+n -> 2n (ok, wild-type)
- 2n+2n -> 4n (also ok, from 4n parents)
- n+2n or 2n+n -> 3n (One 2n and one 4n parent - ok, and offspring produce unviable eggs and pollen except for accidents)
Now you are ready to start. Let me warn you that the pictures in the next few pages are quite large so you can see what is happening. Be patient. You will have to be even more patient as the pods develop (9+ months patient) and maybe several years+ when your seeds grow up to flowering size.
© Copyright 2006+ Arthur Sale
Last Modified: 23 December 2010