Desiccation Sensitivity Characteristics and Low-Temperature Storage of Recalcitrant Quercus variabilis Seed

Abstract

This study aims to investigate the desiccation sensitivity characteristics and the critical moisture content of the recalcitrant Quercus variabilis seed. Additionally, cryopreservation of the recalcitrant seeds were studied. Wild-collected Q. variabilis seeds were used in this research. Differential scanning calorimetry (DSC) was employed to evaluate the critical moisture content and germination indices at different moisture contents were measured. The initial moisture content of the seeds and embryonic axes decreased from 33.1% and 40.9%, respectively, to 10.0%, accompanied by a germination rate decrease of 95.6% and 90.0% to 6.3% and 60.0%, respectively. The theoretical critical moisture content of the embryonic axis was calculated to be 11.55%. As dehydration progressed, drastic changes were observed in the antioxidant enzyme system. Initially, the levels of PRO and SOD in the seeds increased and then decreased, while the levels of POD and MDA consistently increased. The cryopreservation of the embryonic axis was achieved using vitrification. The embryonic axis with a moisture content of 10% had a 15% survival rate when pretreated with PVS2 for 60 min prior to cryopreservation. The results demonstrated that the cryopreservation of the Q. variabilis embryonic axis is possible, but the method needs adjustment to increase the recovery survival rate.