EFFECT OF VARIOUS PARAMETERS ON THE SURVIVAL OF CRYOPRESERVED PRUNUS FERLENAIN IN-VITRO PLANTLETS SHOOT TIPS

The effect of different pretreatment, freezing and thawing conditions on the survival of cryopreserved Prunus Ferlenain shoot tips was inves tigated. High survival (around 50-60%) was obtained when shoot tips we re cryopreserved using the following procedure: excised shoot tips fro m cold-hardened (24h at 4 degrees C) in vitro plantlets were precultur ed at 4 degrees C for 24 h on solid medium supplemented with 5% DMSO a nd 20% proline. Shoot tips were treated with 1 ml of modified PVS-2 cr yoprotective solution for 45 min at 4 degrees C. Cryotubes were then f rozen at 5 degrees C/min down to -40 degrees C and immersed in liquid nitrogen (LN). After rapid thawing at 40 degrees C, shoot tips were ri nsed with a 1.2 M sucrose solution, plated on standard solid medium, m aintained for 2-3 days in the dark and then transferred under standard conditions.