This study describes an efficient and widely applicable droplet-vitrification following cryopreservation for shoot tips of strawberry (Fragaria × ananassa Duch.) cvs. ‘Wonkyo3114’ and ‘Gurumi40’. The shoot tips were precultured in Murashige and Skoog (MS) liquid medium supplemented with sucrose (0.3-0.5M). Precultured explants were osmoprotected with loading solution (LS, C4) containing 20% glycerol and 20% sucrose for 40 min and exposed to dehydration solution (B5) containing 40% glycerol and 40% sucrose for 40 min at 25℃, Subsequently, the explants were transferred onto droplets containing 2.5 µL PVS3 on sterilized aluminum foils (4 ㎝ × 0.5 ㎝) prior to direct immersion in liquid nitrogen (LN) for 1 h. The highest regrowth rate (%) in both the cultivars was obtained when the shoot tips were precultured with MS + 0.3M sucrose for 40 h at 25℃. The cryopreserved shoots tips exhibited 55% regrowth rate by culturing in NH4NO3-free MS medium supplemented with 3% sucrose, 1.0 g/L casein, 1.0㎎/L GA3, and 0.5 ㎎/L BA for 5 weeks and in MS medium supplemented with 0.5 ㎎/L GA3 for 8 weeks. This result shows that droplet-vitrification could be employed as a promising method for cryostorage of strawberry germplasm.
Introduction
Materials and Methods
Results and Discussion
Acknowledgments
References