A comparison of two vitrification methods and the effect of dimethyl sulfoxide in vitrification solution for cryopreservation of Euterpe edulis Martius (Arecaceae)

Abstract Euterpe edulis Martius (Arecaceae) is a native species of the Atlantic Forest hotspot with ecological and economic relevance. Its fruits contribute to biodiversity maintenance by feeding birds and mammals and are valued for their antioxidant properties and applications in the food and cosmetic industries. However, habitat loss and propagation constraints have contributed to the threatened status of this species, reinforcing the need for complementary ex situ conservation strategies. Thus, this study evaluated the cryopreservation of somatic embryos of E. edulis using conventional vitrification and droplet vitrification in association with a modified Plant Vitrification Solution 3 (PVS3) supplemented with different concentrations of dimethyl sulfoxide (DMSO; 0, 5, 10, and 15%). No significant differences were observed between vitrification methods regarding post-thaw recovery. However, PVS3 supplemented with 10% and 15% DMSO promoted higher survival than 0% and 5%, with maximum values recorded at 15% DMSO (67.50% in droplet vitrification and 69.50% in conventional vitrification). Scanning electron microscopy revealed greater structural alterations in somatic embryos at more advanced maturation stages after cryopreservation, whereas transmission electron microscopy showed treatment-dependent differences in cellular ultrastructure, including vacuolization, cell wall disruption, and preservation of nuclear organization in surviving cells. Elemental analysis by energy-dispersive X-ray spectroscopy (EDS) revealed differences among cryopreservation treatments, with higher carbon intensity observed in treatments showing greater post-thaw survival and lower carbon intensity associated with reduced survival. This technique demonstrates potential for preserving germplasm of endangered E. edulis adult plants and can strategically support genetic improvement programs.