Slow growth storage and cryopreservation—tools to facilitate germplasm maintenance of vegetatively propagated crops in living plant collections

In living plant collections, vegetatively propagated accessions are outstanding material with respect to vulnerability and labour amount. This is also true for the main vegetative material, held in the IPK, Gatersleben. A survey of the preservation of potato, garlic and other alliums, mint and yam is given. More than 630 accessions are in slow growth conditions. Amongst them, 99 clones of garlic and 35 of shallot have been tested to be virus-free. Cryopreservation is routinely applied for potato using the droplet method. The cryo-collection contains more than 1000 accessions, a part of which has been integrated from another collection, formerly established at Braunschweig. Cryopreservation of garlic has been used to store the accessions of the European core collection. Cryopreservation is successful in three Dioscorea species using a combination of the original vitrification with the droplet method. Investigations about morphogenesis and ultrastructural cell parameters before, during and after cryopreservation were included in these activities.