Germplasm Conservation - plant tissue and organ culture

Totipotent plant cells and shoot tips can be freeze-preserved in liquid nitrogen (-196? C) for long periods, and when required they can be thawed and cultured to regenerate whole plants. Alternatively, for short term storage, the proliferating shoot cultures or roots can be incubated at growth-limiting conditions, such as decrease in temperature (4-12?c) or low nutrients. Such cultures have been shown to retain viability for 1-3 years, without a subculture. Root cultures have been kept for 25-30 years.