Cryopreservation of wheat (Triticum aestivum L.) egg cells by vitrification

Abstract

A procedure has been developed for the cryopreservation of wheat female gametes. The procedure involves loading the cells with 25% concentrated vitrification solution consisting of 30% glycerol, 10% sucrose, 120 mM ascorbic acid (AA) and 5% propylene glycol (PG), dehydration in 80% concentrated vitrification solution, droplet vitrification and storage in liquid nitrogen, unloading and rehydration of the cells by gradual addition of isolation solution. Supplementation with AA significantly increased the proportion of viable egg cells after de- and rehydration. During the early phase of rehydration AA reduced the probability of membrane damage caused by rapid water uptake. Maintaining the temperature of the cells at 0°C during the de- and rehydration processes increased cell survival. Microscopic examination of the semi-thin sections of untreated and viable cryopreserved cells revealed that the vitrification process might cause changes in cell structure.