Cryopreservation of axillary buds of a Eucalyptus grandis x Eucalyptus camaldulensis hybrid

This paper presents preliminary results from a study to develop methodology for the cryopreservation of axillary buds from an in vitro hybrid Eucalypt us grandis (W. Hill ex Maiden.) x Eucalyptus camaldulensis (Dehnnh.), maint ained for use in a genetic modification programme. Axillary buds were encap sulated in an alginate gel, precultured on media containing elevated levels of sucrose, or a combination of sucrose and glycerol. Encapsulated buds we re then dehydrated by evaporation prior to a two-step freezing process in l iquid nitrogen. Eighteen percent of shoot explants survived freezing when s ucrose alone was used as a protectant against dehydration and cryopreservat ion. Significantly higher survival (49%) was obtained with the incorporatio n of glycerol into the protocol. Following cryopreservation, shoots appeare d to develop normally, with no evidence of adventitious meristems.