Medium Term Preservation of Wild Crocus (Crocus Hyemalis and Crocus Moabiticus) Embryogenic Callus

Slow growth in vitro preservation using different osmotic agents (sucrose, mannitol and sorbitol) at different concentrations (0.0, 0.1, 0.2, 0.3 and 0.4 M) and at reduced temperatures (4, 8 and 24 °C) was investigated. Embryogenic calli of crocus species were used. Preservation of calli on a medium supplemented with 0.2 M sucrose, mannitol or sorbitol under complete darkness was able to decrease the growth rate and maintain explant quality for 12 weeks. Calli preservation at 8 oC in the dark was also able to decrease the growth and maintain explants in a better condition for 12 weeks before the next subculture. Also, the appearance of some physiological disorders like browning and tissue death was observed as the concentrations of osmotic agents increased, the temperature lowered and the preservation period extended.