Cryopreservation of Byrsonima intermedia A. Juss. embryos using different moisture contents.

摘要

Byrsonima intermedia is a native medicinal species of Brazilian Cerrado which sexual propagation is limited by reduced seed germination rate and seedling emergence. The cryopreservation technique of embryonic axes is a viable alternative for the conservation of genetic diversity. In this context, the objective of this study was to evaluate the effect of freezing in liquid nitrogen on Byrsonima intermedia zygotic embryos at two moisture contents 15 and 25%, using PVS2 as cryoprotectant. After isolation, embryos were sterilized and either inoculated directly on the culture medium, pre-frozen for 20 minutes in PVS2 solution or cryostored in liquid nitrogen. After submitted to these treatments, embryos were inoculated on 50% WPM and transferred to a growth room. No significant differences between the treatments and moisture contents were observed. Embryos inoculated directly on the culture medium without PVS2 treatment or freezing showed 70% regeneration. Embryos directly immersed in liquid nitrogen presented low germination rate. The use of PVS2 improved embryo in vitro regeneration following cryostorage in liquid nitrogen.