Evolution of DMSO concentration in garlic shoot tips during a vitrification procedure

In this paper, the evolution of dimethylsulfoxide (DMSO) concentration and moisture content (MC) of garlic shoot tips was studied during the course of a vitrification protocol using the PVS2 vitrification solution. DMSO concentration of shoot tips increased rapidly, reaching 34.1 mg per g fresh weight after 20 min of PVS2 treatment and remained stable afterwards, while moisture content decreased from 82 to 60 percent, reaching 53 percent after 60 min. A reverse process was observed during unloading. There was a highly significant negative correlation between shoot tip moisture content and DMSO concentration during the dehydration and unloading treatments. Using unloading solutions with osmolarities between 0.42 and 2.29 Osm led to very different shoot tip MCs, between 63.55 and 81.24 percent, while DMSO concentration was between 14.83 and 19.97 mg per g fresh weight. After 24 h on recovery medium, DMSO concentration of shoot tips had decreased to 3.2 mg per g fresh weight.