Droplet-vitrification cryopreservation of Tulipa tarda Stapf. apical meristems

Abstract

The present study provides an efficient cryopreservation protocol for Tulipa tarda cultured in vitro. Apices were excised from bulblets cultivated on MS medium, supplemented with 60 or 90 g l− 1 sucrose. Half of the bulblets were subjected to a cold treatment at 5 °C for 10 weeks, before exposure of the apices to loading solution (LS) and plant vitrification solution 2 (PVS2). Ten weeks after rewarming and culture on recovery medium, 100% regrowth rates were obtained for cold treated explants cultured on 60 g l− 1 sucrose after 30 and 60 min exposure to PVS2. Cold treatment significantly improved the recovery rates of most of the cryopreserved apical meristems while an enrichment of the culture medium with higher sucrose concentration (90 g l− 1) did not improve regrowth of the apices.