Cryopreservation of Vasconcellea quercifolia St.-Hil (Caricaceae) Zygotic Embryos

Abstract

Vasconcellea quercifolia A. St.-Hil. (Caricaceae) is a tropical fruit species native to Brazil, with a great importance in plant breeding programs. The V. quercifolia has a resistance to the main diseases of Caricaceae, Papaya Ringspot Virus (PRSV). Considering its potential, cryopreservation becomes a tool for the conservation of this species. The objective of this paper was to study the cryopreservation of V. quercifolia zygotic embryos through dehydration in silica gel. Excised zygotic embryos were dehydrated in silica at 0, 20, 40, 80 and 100 minutes and then inoculated in MS medium. The percentage of germinated and recovered embryos, and growth analysis were evaluated, besides water content. Subsequently, they were acclimatized in a growth room with temperature controlled. For cryopreservation, the embryos were excised and dehydrated in silica for 0, 20, 40 and 60 minutes, immersed in Liquid Nitrogen (LN) for 1 hour, thawed in Recovery Solution (RS) and inoculated in MS medium. After 30 days, the percentage of germinated and recovered embryos was evaluated. The silica gel promotes a fast dehydrate of embryos. The results showed that embryo dehydration affected seedling development, and dehydration for over 20 minutes showed a reduction in all evaluated parameters. The plantlets regenerated from embryos dehydrate survive the acclimatization. It was possible to cryopreserve the V. quercifolia zygotic embryos when the dehydration time of 20 minutes by silica gel was used.