BIOTECHNOLOGY AND THE CONSERVATION OF FOREST GENETIC-RESOURCES - IN-VITRO STRATEGIES AND CRYOPRESERVATION

In vitro techniques have a clear role within ex situ conservation stra tegies for trees and crop genetic resources, particularly where it is important to conserve specific genotypes or where normal propagules su ch as recalcitrant seed may not be suitable for long-term storage. The se involve the use of conventional micropropagation, restricted growth techniques and cryopreservation. Although these techniques have been used primarily with herbaceous species, increasing attention is being given to woody species. Cryopreservation techniques for both woody and herbaceous species and new approaches which do not require freeze-ind uced cell dehydration, referred to as the 'encapsulation-dehydration' and the 'vitrification' techniques are described. Illustrative data ar e presented for the cryopreservation of willow using the encapsulation -dehydration technique.