Cryopreservation of lateral buds of in vitro-grown innala plants (Solemostemon rotundifolius) by vitrification

We succeeded in cryopreserving of innala (Solenostemon rotundifolius) in vitro-grown young lateral buds by vitrification. Nodal segments from in vitro-grown shoots (2-4 mm in length) were cultured on MS medium containing 0.1M sucrose in Petri dishes for 3 weeks under 16-h photoperiod at 25 degree C. This pre-growth induced a large number of uniform young lateral buds. Nodal segments (0.5 to 1.0 mm in length) with two lateral buds were dissected from the shoots and precultured with 0.3 M sucrose for 2 days at 25 degree C. They were then treated with loading solution containing 2 M glycerol and 0.4 M sucrose (LS solution) for 20 min at 25 degree C and dehydrated with the PVS2 vitrification solution for 18 min at 25(C prior to either rapid immersion in liquid nitrogen. Surviving lateral buds resumed growth within 3 days and developed shoots without intermediary callus formation. The average growth recovery after cryopreservation amounted to 85%.