Seed preparation
Orchid seeds are about the size of dust particles, have no endosperm and only a tiny embryo with almost no food reserve. In nature each seed must be colonised by a mycorrhizal fungus that feeds it. In cultivation, seed is surface-sterilised and sown on a sterile nutrient agar medium in a flask (asymbiotic sowing), or sown with a compatible fungus in a laboratory. Without sterile technique, moulds and bacteria quickly overgrow the nutrient-rich medium.
