Assessing storage needs
Most species possess 'orthodox' (where drying will not kill them) seeds that remain viable when dried to the low moisture levels necessary for long-term storage. ‘Recalcitrant’ seeds are more or less completely intolerant of drying and rapidly die when they are dried. As the name suggests, species with ‘intermediate‘ seeds can withstand partial drying but are very short-lived if they are stored at sub-zero temperatures. Recalcitrant seeds are often large and fleshy with thin seed coats and the MSBP seed collectors will be cautious when confronted by such seeds on collecting missions. The Seed Information Database can be used to assess whether seeds from a particular species, genus or family are likely to possess recalcitrant or intermediate seeds.
If a species has been collected that is closely related to a known recalcitrant or intermediate species or has large fleshy seeds, MSBP scientists will test for dessication tolerance before transferring the seeds to a dry room. This test involves viability tests before and after drying on a small sample of the collection.
More information can be found in our series of information sheets, Identifying desiccation-sensitive seeds.