Survival and State of Garlic Explants of Two Lithuanian Cultivars after Cryopreservation

Cryopreservation features of Lithuanian garlic (Allium sativum L.) cultivars `Ziemiai' and `Dangiai' were investigated. The survival rate and state of explants, depending on the type of explant, and dehydration conditions were evaluated in the experiment. Explants isolated from cloves and bulbils were dehydrated with a plant vitrification solution 3 (PVS 3) containing 50% w/v glycerol and 50% w/v sucrose in liquid MS medium. Three different exposure durations of 1.5, 2, and 3 h in PVS3 solution were applied at 0 degrees C. Unloaded stem domes were planted in Petri dishes with MS medium supplemented with 1 mg L (-1) naphthaleneacetic acid (NAA) and 6-dimethylallylamino purine (2-iP) on 0.8% plant agar. The obtained results showed that the cryopreservation in liquid nitrogen reduced the survival rate of explants by 20-40%. The average number of surviving explants after freezing reached 64.3% for both cultivars. Cultivar `Ziemiai' showed a 24% higher capability for survival than `Dangiai'. The total number of surviving explants of `Ziemiai' reached 76.1%. Explants from bulbils were 23% more effective for cryopreservation compared to cloves. Evaluation of the effect of dehydration duration showed that the survival rate of the explants from bulbils of both cultivars was highest after treatment with PVS3 for 3 h and reached 91%. Treatment in PVS3 solution for 2 h was sufficient for survival of explants from cloves. Obtained results confirm that the efficiency of garlic cryopreservation depends on complex factors.