Orchid seed is the key to everything we do at the Writhlington Orchid Project. It is from orchid seed that we get the plants that we sell to make money for our trips. It is also these seeds that will grow up to make up our collection that is taken to shows. I mentioned seed earlier this month, so will not dwell on all of the ins and outs of orchid seed.
I will mention that there are lots of seeds in one seed pod. Hundreds of them! Thousands and, in many cases, millions! All of this seed needs sorting before it can be sown.
All of our seed is stored in the fridge in small, labeled jars, but before it can be refrigerated it must be dried. Now we have a hi-tech seed drying chamber to do this in a matter of days, but in the past the seed had to be left in paper envelopes, in a large box on a top shelf. We found one such box today and have been going through the seed, packet by packet, testing for viability.
Viability testing is one of the most useful things we do in the labs. Sure, sowing the seed is important, as is splitting the seeds up, but if the seed is not viable, i.e. not going to germinate anyway, there is no point in it even being sown. For this reason, before it is refrigerated, all seed must be viability tested.
As hi-tech as it sounds, viability testing is a relatively simple task. A small sample of the seed is placed on a microscope slide and examined. Under a microscope, it is clear whether or not an embryo is present in the seed. No embryo = non-viable seed.