In order for orchid seeds to germinate, they are dependent on a special symbiosis fungus. Since symbiotic sowing under sterile conditions is complex and delicate, research was carried out into simple alternatives. The result was an asymbiotic seeding, with a medium replacing the mycorrhizal fungus. Here we explain how to prepare this medium for sowing.
Orchid seeds should be grown on special breeding ground from specialist retailers
Equipment and material at a glance
In order for the sowing of orchid seeds to take a successful course, laboratory equipment is not required. The plan can succeed with the following equipment:
- Test tubes with heat-resistant stoppers
- wire rack
- cooking pot
- pressure cooker
- Postal scale for weighing culture medium powder
- glass funnel
- culture medium powder
- Distilled water
- aluminum foil
Suitable culture medium powder is available from specialist retailers and online shops, such as Sigma culture medium P6668. If you are willing to dig a little deeper into your pocket, you can opt for instant media that are tailored to the specific orchid species. SBL-A seeding medium gets Phalaenopsis and Vanda seeds going, while SBL-C gets Cattleya and Dendrobium seeds germinating.
Instructions for the preparation of culture medium
All vessels and tools are thoroughly cleaned and disinfected in advance. Then stir the culture medium powder weighed with the letter scale into the distilled water and fill the solution into the saucepan. Bring the liquid to a boil and let it simmer gently for 2 minutes. It is important to note that the solution does not foam.
Now fill the liquid culture medium into the test tubes via the glass funnel and loosely put on the heat-resistant stopper. Place the culture vessels in the wire stand, cap each jar with aluminum foil, and place in the pressure cooker. Fill in the minimum amount of water allowed according to the manufacturer's description and close the pressure cooker.
The water is heated to 120 degrees to generate a pressure of 0.8 bar. This state must be maintained for 15 minutes. Ideally, let the test tubes cool overnight. Now screw the caps tight and label each glass. If no contamination has developed in the jar after a waiting period of 1 week, the culture medium can be used.
tips
If the package insert states that the culture medium granules do not contain a gelling agent, please add this. Agar-agar, which can be bought inexpensively in supermarkets, has proven itself well in practice. A dosage of 6 to 7 grams per liter of water is usually appropriate.