Longevity, Storage, and Deterioration

Abstract

Many seeds are capable of surviving dehydration at maturity, in which state they can survive for long periods (up to hundreds of years in some cases) and resume growth when rehydrated. However, deteriorative chemical processes continue in dry seeds, resulting in their gradual loss of vigor and eventual death. The rate of loss of seed viability is dependent primarily on their moisture content and the temperature at which they are stored. High temperatures and moisture contents accelerate seed deterioration, so low temperatures and moisture contents are used for long-term seed storage for germplasm conservation. While many processes may contribute to seed deterioration, it is likely that reactive oxygen species and related chemical oxidation are primarily responsible. Dormancy of some seeds that is alleviated by dry storage (after-ripening) may also be due to such oxidation events that could inactivate inhibitors or modify components of molecular regulatory pathways. Some seeds, including many tropical species, do not develop desiccation tolerance and are termed “recalcitrant.” This property renders them difficult to store, complicating the preservation of their diversity in seed banks.