Orchid Propagation Techniques
Dr. Sheena McKendrick, Ceiba Intern, March 2000
A research program testing a variety of techniques for raising orchid seedlings was conducted from February
2000 to mid-2001. The original purposes of the program were to find methods using inexpensive materials to successfully
rear orchids from seeds. Such techniques could be used to propagate orchids from wild stock, and then reintroduce them
to native habitat, or to produce orchids for sale and funnel the proceeds back to reserves from which the original seed stock
had come. Due to lack of funding, neither long-term goal was met; however, we learned a great deal about orchid propagation
that may be of use to others with similar interests.
In vitro germination of orchid seeds
Orchid seeds are not like other seeds in that they are tiny (they are often referred to as dust seeds) and contain few
food reserves. In nature they usually will not germinate unless infected by a particular fungus, which feeds the
young plants with all the sugars and nutrients they need until the plants are large enough to produce their own food. Once
the seed has germinated it produces a fairly undifferentiated mass of cells called a protocorm (see picture). All being well
this protocorm will continue to grow for many weeks, months or even years depending on species, until large enough to produce
leaves and roots. In terrestrial orchids it is vitally important that the orchid/fungus relationship is maintained as the
protocorm is underground or under leaf litter and cannot produce any food of its own. In epiphytic orchids the protocorms
are often green, and thus can produce some food of their own. Epiphytic orchids are still thought to be dependent on the fungus
for the germination, but little research has been done in this area and so nobody knows for sure.
In in vitro germination the seeds are germinated under sterile conditions in glass dishes or jars on a gel-based
medium which contains all the sugars and minerals the seeds need to germinate and grow. The media, to a certain extent, mimic
the nutrients which would have been provided by the fungus and allow the seeds to germinate and grow without it. The media
and the jars used are first sterilized by subjecting them to high temperature and pressure for 15 minutes in an autoclave,
then the media allowed to cool and set. Sterile conditions for pouring the media and sowing the seeds are obtained using a
laminar air-flow bench. This bench is enclosed on all three sides and the top. Air is sucked in from the back of the bench
and blown through filters over the bench. The filters filter out any bacteria and fungi in the air and the air flow normally
prevents any spores in the air just outside the bench from floating in. Thus, if the bench is thoroughly sterilized with alcohol
before work commences, and care is taken not to introduce contamination, it should remain sterile. Sterility is important
as any bacteria or fungi introduced to the flasks will grow much quicker than the seedlings and may over/run and kill them.
Two methods employed for germinating the seeds
from green capsules (left). The inside of orchid capsules, if intact, are naturally sterile. Therefore if you sterilize the
outside of the capsule, where bacteria and fungi can collect, and cut open the capsule under sterile conditions then the seeds
should be sterile. This method has the advantage that the seeds themselves do not need to be sterilized (which can sometimes
lead to damage). In addition, some seeds, if taken from capsules which are almost ripe, germinate quicker than those taken
from mature capsules as the dormancy mechanisms are not yet in place. It has the disadvantage that once opened all the seeds
from a capsule must be sown or discarded.
2. Sowing from mature seeds. Once a seed capsule has opened naturally, the seeds are no longer sterile. The seeds
thus need to be sterilized, usually using a solution of sodium hypochlorite (bleach), calcium hypochlorite or hydrogen peroxide.
The seeds are shaken in a solution of sterilant containing a drop of detergent to wet the seeds, then rinsed in sterile water
and planted on to the medium. This method has the advantage that seeds can be collected, air-dried, stored for many months
in the fridge and used when needed. Germination from mature seeds has already been achieved successfully with Trichopilia
in vitro propagation program tests were carried out at a local university where we were provided access an autoclave, laminar air-flow cabinet and growing facilities
necessary to germinate and grow the orchids under sterile conditions. Ceiba would like to thank Dr. Nelson Zaballa and
Dr. Stella de la Torre for their generosity, and Monica de Navarro for her invaluable expertise and support.
Without their tireless assistance, this research would not have been possible.
Seed germination can bea very important tool in the conservation of wild orchids through the propagation and distribution
of rare and endangered orchids, and potentially through the propagation and sale of unusual and ornamental species in order
to provide funds for the on-going protection of habitat reserves.
Orchid Propagation Manual
To download a copy of Ceiba's Orchid Propagation Manual select from the following formats:
English - MS Word (.doc - 62k) . English
- Adobe Acrobat (.pdf - 46k)
Spanish - MS Word (.doc - 89k) . Spanish
- Adobe Acrobat (.pdf - 49k)
If you are unable to view the Propagation Manual, please contact Ceiba to receive a copy.