Exploration on Cryopreservation Conditions of Plum Shoot Tips by Encapsulation-vitrification

Using local germplasm of crisp plum in Guizhou Province as materials,shoot tips was cryopreserved by encapsulation-vitrification,and effects of sodium alginate concentration,calcium chloride concentration,the sucrose concentration of osmotic protective agent,and exposure time to PVS2 on the survival rate of shoot tips were investigated in the present work.Precultured shoot tips were encapsulated and simultaneously osmoprotected with a loading solution of 2 mol / L glycerol and 0.4 mol / L sucrose for 30 min.Osmoprotected and encapsulated shoot tips were dehydrated with a highly concentrated vitrification solution for 120 min at 0℃ prior to direct immersion in liquid nitrogen for 24 h.After rapid thawing in water at 37℃ for 3 min,the shoot tips were rinsed in a 1.2 mol / L sucrose solution for twice at room temperature and transferred onto the recovery medium.The cultures were kept in dark for one week prior to exposure to the light.The best survival rate of encapsulation vitrified shoot tips amounted to 21% after recovery training.