Preparation of the workspace.
This procedure will need to be carried out each time you make media or manipulate seed, protocorm and developing seedlings.
Try and place your workspace in a draught-free area and, using your chosen sterilant, thoroughly clean and wipe down the whole of the inside and any plastic sheet that you may be using, together with the area immediately surrounding your workspace. Spray and leave for at least 15minutes for the sterilant to do its job.
Anything, (with the possible exception of hot just processed media), that goes into this workspace from now on must be dipped in sterilant before entry.
For preparation of media, leave it empty and follow instructions for media preparation.
For sowing or replating, wipe down the area as before and follow instructions for seed preparation.
Preparation of media.
Choose the most appropriate media for the orchid seed that you intend to sow, epiphytes and terrestrials generally require different recipes and there are many which are supplied as a dry powder so you have only to add water and autoclave. A good general one for most epiphytes is one called P6668, this is readily available from several sources, there is a similar one called Orchimax. If diluted, this recipe will also be suitable for some British native terrestrials but they will also do well on a variation of M551. If you can source the correct fungi symbiont then you could also try the ‘symbiotic, method for some of the terrestrials. I have not included protocols for this here. There will be a list of suppliers of media at the end of this article.
I strongly recommend that you use one of the readily-available media formulations, this will ensure consistency and repeatability.
If you are sowing seed for the first time then I would recommend that you purchase the just-add-water ones, this avoids the need to also buy activated charcoal or a setting agent such as agar or any product designed to control Ph … it will all be done for you. Any following instructions refer to this type of media. Most pre-mixes are sold as suitable to prepare multiples of 1 litre, 1,10,50 etc. If you want to make 1litre then buy a 1litre pack, avoid the temptation to buy a larger pack and then remove smaller amounts since some ingredients are present in such small quantities that it may be impossible to dispense a balanced sample.
Assemble all the vessels and prepare the autoclave (pressure cooker), whilst the media is being sterilised you can then prepare your workspace, ready to receive the hot vessels. Remember the aluminium foil to cover the lids.