Cryopreservation of Malus shoot tips and subsequent plant regeneration

Abstract

The aim of the present study was to investigate the importance of the preculture conditions on the survival of apple (Malus domestica Borkh., cv. Romus4 and rootstock M106) shoot tips cryopreserved using a combined droplet vitrification procedure. Preculture was critical for the survival of apple shoot tips after cryopreservation. Among the different tested sugars and sugar alcohols (glucose, sucrose, mannitol and sorbitol) sucrose treatment for 24 h was the most efficient one. After thawing and transfer of shoot tips on recovery medium the highest regrowth rates (68% for cv. Romus4 and 62% for the rootstock M106) were achieved after using the PVS2 vitrification solution. Plants regenerated from cryopreserved shoot tips did not displayed any sign of morphological alteration or abnormalities in growth in comparison with control plants.