Cryopreservation of in vitro -grown shoot tips of Cleome rosea Vahl (Cleomaceae) using the V cryo-plate technique

This report highlights the first successful cryopreservation of in vitro shoot tips of Cleome rosea , achieved by the vitrification technique using aluminum cryo-plates (V cryo-plate). The effects on survival and recovery of C. rosea shoot tips of different plant vitrification solutions (PVS2 and PVS3), light intensity (standard and dim light), and 6-benzyladenine (BA) supplementation (0.10, 0.25, or 0.50 mg L −1 for 1 or 3 wk) in the recovery medium were investigated. Cryopreserved shoot tips showed high regeneration frequencies when treated with PVS2 and PVS3, reaching survival frequencies of 97 and 70%, respectively. When placed onto medium without growth regulators, recovery of cryopreserved shoot tips did not exceed 33% (obtained with PVS2) or 23% (PVS3). Supplementation of recovery medium with 0.5 mg L −1 BA for 3 wk increased both survival and recovery to 100% after cryopreservation following treatment with either PVS2 or PVS3. These values were maintained even when shoot tips were cultured in the presence of 0.10 mg L −1 BA for 1 wk. Maintenance under dim light resulted in better phenotypic characteristics of plants produced from cryopreserved shoot tips.