Determination of glassy state by cryo-SEM and DSC in cryopreservation of mint shoot tips by encapsulation-dehydration

ALINE SCHNEIDER TEIXEIRA; M. ELENA GONZALEZ-BENITO; ANTONIO D. MOLINA-GARCÍA

PLANT CELL TISSUE AND ORGAN CULTURE

SPRINGER

Lugar: Berlin; Año: 2014

0167-6857

Cryopreservation of mint shoot tips grown in vitro (Mentha ×piperita) was performed after encapsulation in alginate beads. Encapsulated shoot tips were first pre-cultured in sucrose enriched medium (0.75 M) and then dried under a sterile air flow (0-6 hours). After cooling in liquid nitrogen and warming in a warm water bath, alginate beads were transferred to solid culture medium for 4 weeks. The effect of dehydration time of the encapsulated shoots was evaluated for water content, cooling and warming rates, ice crystal formation and cellular vitrification, by using low-temperature scanning electron microscopy (cryo-SEM) and differential scanning calorimetry (DSC). Viability of the recovered material showed a close relation between the dehydration time, cooling and warming rates, ice formation avoidance and tissue vitrification. At short drying periods (up to 3 hours), ice crystals were formed and the viability was low or absent. After longer drying periods (5 and 6 hours), both beads and specimens became vitrified.