Effects of post-harvest storage of Allium sativum bulbs on the cryopreservation of stem-discs by encapsulation/dehydration

Cryostorage of vegetatively propagated Allium species is important for the long-term conservation and sustainable use of Allium germplasm. Cryopreservation of clonally-propagated crops such as Allium is a complex, multicomponent process where both cryogenic and non-cryogenic factors can influence the outcome of storage. This study demonstrates that the duration of post-harvest storage of bulbs significantly affected the frequency of shoot regrowth following cryostorage of Allium sativum. Post-cryostorage survival of stem-disc quarters was highest (75%) following a storage period of 5 months. The highest frequency of regrowth (55%), after 4 months of storage, corresponded to an average regeneration frequency of 1.9 shoots per stem-disc quarter. These results show the importance of the physiological state of bulbs, and the need to optimise the duration of storage to break bulb dormancy, in order to improve the cryopreservation of A. sativum stem-discs using encapsulation/dehydration.