Cryopreservation of Mediterranean and tropical crops
Many of the world’s major food plants produce orthodox seeds which are tolerant to extensive desiccation and can be stored dry at low temperatures for extended time spans. In contrast to orthodox seeds, the conservation in the form of seeds of a considerable number of species, predominantly tropical or subtropical, is impossible because the seeds they produce are recalcitrant or because they are propagated vegetatively. Cryopreservation (liquid nitrogen, -196°C) is currently the only option for safe and cost-effective long-term storage of genetic resources of such problem species.
Dramatic progress has been made during the last 20 years in plant cryopreservation, thanks to the development of efficient and broadly applicable vitrification-based techniques. However, if tolerance to liquid nitrogen exposure has been demonstrated for a large number of plant species, the large scale, routine applications of cryopreservation in genebanks is still restricted to a limited number of examples. This is particularly true for tropical plant species, which do not possess the dehydration and cold adaptation mechanisms which are found in temperate species.
Priority areas for research in the area of cryopreservation include the development of new (vitrification-based) techniques and their application to additional species, including vegetatively propagated and recalcitrant species, with a strong focus on tropical species; fundamental studies aiming at understanding mechanisms related to resistance to dehydration and liquid nitrogen exposure; evaluation of the potential use of cryopreservation to eliminate viruses (a process termed cryotherapy); and studies on the management of cryopreserved collections and on the integration of cryopreservation in global conservation strategies.
The Cryopreservation project aims at developing cryopreservation techniques for yam, a vegetatively-propagated crop of major importance for the food security of tropical countries, and applying these techniques to other crops.