Cryopreservation of brown algae gametophytes of Undaria pinnatifida by encapsulation–vitrification

The cryopreservation of gametophytes of Undaria pinnatifida by encapsulation–vitrification was studied. The effect of the composition of the vitrification solution (VS), the composition and concentration of the loading solution (LS), the duration of loading and dehydration treatments and the washing method on viability of algae were investigated. The highest viability index for female and male gametophytes was 31.2% and 26.0%, respectively, which were obtained by loading alginate beads with a mixture of 2 M glycerol and 0.6 M sucrose for 120 and 90 min at 25 °C, dehydrated with PVS2 for 50 and 40 min at 0 °C and washed with a 1.2 M sucrose solution. Intact sporophytes developed from gametophytes cryopreserved have been observed.