Cryopreservation, that is, the viable storage of cells at the temperature of liquid nitrogen (-196°C), has wide relevance in many areas of pure and applied biology. Examples of its very successful use can be found in the storage of microbes and of semen (1). More recently, attention has been given to the development of cryopreservation methods for embryos, including those of humans, tissues, and organs for transplantation and blood components. In the context of plant research, realization of the potential applications of cryopreservation has been somewhat latent. However, several clear areas for application can be identified that involve the need to store exact genotypes in a stable state.