Induction of longevity in primed seeds

Priming of seeds is generally intended to reduce time to germination, often leading to improved emergence. However, as a negative side effect, priming reduces longevity of seeds. We studied the possibilities to obtain primed seeds with reduced time to germination but with longevity similar to that of untreated seeds. For several species tested we found that the desired longevity could be obtained by keeping the seeds, after a priming treatment, under a mild water and / or temperature stress for a period of several hours to days. Time to germination did not increase again due to such a treatment. Optimal duration and degree of water stress were strongly temperature dependent. The methods applied to obtain primed seeds without loss of longevity are very similar to those used to induce desiccation tolerance in germinated seeds.