ABSTRACT
Cryopreservation is the preservation of viable biological samples at ultra-low temperatures (-196°C). Cellular metabolic activities are arrested by cryopreservation due to the low temperature and the unavailability of liquid water. Cryopreservation techniques provide a means of preserving valuable germplasm for a long period of time under stable conditions. Cryopreservation of plant cell cultures is used for the preservation of morphogenetic potential, biosynthetic capability, and selected mutants. Protocols have been developed for the cryogenic storage of many plant cells, tissues, and organs of many plant species. The collection and conservation of germplasm are necessary to maintain a broad gene base for crop improvement. The irretrievable loss of naturally occuring germplasm is a major concern of plant breeders throughout the world. The feasibility of applying plant cell tissue culture technology to crop improvement relies on in vitro plant regeneration. Many plant tissue cultures decline or lose regeneration potential and increase in developmental and genetic anomalies during repeated subculture.
