Cryopreservation of in vitro grown shoot tips of cherry and sweet cherry by one-step vitrification

In vitro grown shoot tips of cherry (Prunus jamasakura Seib. cv. Sendaiya) were successfully cryopreserved by one-step vitrification. After the last subculture, 3-week-old shoots were cold-hardened at 5 degrees C for 45 days, Excised 3-mm shoot tips were precultured on solidified Murashige and Skoog medium supplemented with 0.7 mol l(-1) sucrose for 1 day at 5 degrees C, Following preculture, the shoot tips were transferred to a 2-ml plastic cryotube, and the highly concentrated cryoprotective solution PVS2 was then added (vitrification method). After treatment with PVS2 at 25 degrees C for 105 min, the shoot tips were directly plunged into liquid nitrogen. After rapid thawing, the shoot tips were plated on agar medium. The survival rate was about 80% regardless the time of storage in liquid nitrogen from 1 day up to 10 months, This Vitrification method was successfully applied to two cherry cultivars and five sweet cherry cultivars. (C) 1997 Elsevier Science B.V.