Plant Cryopreservation: From Laboratory to Genebank

Cryopreservation at ultra-low temperature (-196°C) is an important approach for the secure long-term storage of plant species, which are vegetatively propagated and/or produce recalcitrant seeds. Although previous progress has relied on empirical applications for different tissues and species, advancements in current applications now emphasise: (1) Fundamental studies to examine the factors influencing the cryopreservation process towards more 'targeted' improvements in techniques; (2) Applications of this technology in genebanks towards the establishment of cryopreserved germplasm collections; and (3) Charac- terisation of germplasm recovered from cryopreservation. These advancements in cryogenic storage will be illustrated by a selec - tive study, which investigates the in vitro conservation of Allium genetic resources using an encapsulation/dehydration procedure for the long-term cryogenic storage of A. sativum (garlic) germplasm. The challenges of fundamental biochemical studies will be highlighted to include the characterisation of tubulin, polyamine and total fatty acid analysis, towards understanding their effects on the different stages of cryopreservation. Exercises in the validation of the encapsulation/dehydration protocol will be compared to an existing Plant Vitrification Solution (PVS)-based protocol that has been used to conserve core collections of A. sativum at the IPK Gatersleben Genebank. The implementation of strategies to assess the genetic stability of A. sativum explants recovered from the encapsulation/dehydration protocol will be discussed as a future requirement in the long-term conservation of A. sativum germplasm.