Abstract: Maturation drying is a terminal event of seed development. Seeds can be categorized into ortho-dox, recalcitrant and intermediate seeds depending on their storage behaviour. A number of processes or mechanisms have been suggested to confer, or contribute to, desiccation tolerance of seeds. Different pro-cesses may confer protection against the consequences of loss of water at different hydration levels, and the absence or ineffective expression of one or more of these could determine the relative degree of desiccation sensitivity of seeds of individual species. The processes or mechanisms that have been implicated in desic-cation tolerance of seeds to date are: intracellular de-differentiation; metabolic 'switching off'; presence and efficient operation of antioxidant systems; accumulation of putatively protective molecules including late embryogenic abundant proteins, sucrose and certain oligosaccharides or galactosyi, amphipathic mole-cules, as well as oleosins; and the presence and operation of repair systems during rehydration of seeds.

Key words: Desiccation tolerance