Comparing encapsulation-dehydration and droplet-vitrification for cryopreservation of sugarcane (Saccharum spp.) shoot tips

In this study, in vitro shoot tips of two sugarcane clones were successfully cryopreserved using encapsulation-dehydration and droplet-vitrification with two vitrification solutions, PVS2 and PVS3. For both clones, encapsulation-dehydration induced significantly higher recovery, reaching 60% for clone H70-144 and 53% for clone CP68-1026, compared with droplet-vitrification in which recovery was 33–37% for clone H70-144 and 20–27% for clone CP68-1026. Optimal conditions included preculture of encapsulated shoot apices for 24 h in liquid medium with 0.75 M sucrose and dehydration with silica gel to 20% moisture content (fresh weight basis) before direct immersion in liquid nitrogen. With both protocols employed, regrowth of cryopreserved samples, as followed by visual observation, was always rapid and direct.