Seed Longevity

For so-called orthodox species, such as most cereals and legumes, the seeds store best if cold and dry. However, they do not store forever, and one of the most important and costly genebank operations is testing whether sufficient seeds are viable and, if not, growing the viable seeds out to refresh the accession. At present, most genebanks err on the side of caution and assess the viability of accessions on a strict schedule, every 5 or 10 years. Reducing seed moisture content to the right level and maintaining dry seeds at constant low temperature can increase longevity by decades. The longevity depends on a number of variables. Fundamental research on seed longevity thus has the potential to reduce the frequency and therefore the costs of viability testing and of regeneration and so increase genebank efficiency.

Under the leadership of IRRI, CGIAR genebanks research better approaches to viability testing, including automated germination tests and non-destructive methods. More accurate models to predict longevity can reduce the number of times an accession needs to be tested. Together, this research optimises the preparation of seeds, the number of seeds used and the testing schedule for each accession. There is a particular focus on wild species and forage crops, which are particularly demanding because less is known about them.