Cytological and physiological changes in recalcitrant Chinese fan palm (Livistona chinensis) embryos during cryopreservation

摘要: Cytological and physiological changes during cryopreservation were investigated in Livistona chinensis embryos excised 42 weeks after flowering. Both dehydration freezing caused numerous cellular ultrastructural alterations. Dehydration seriously impaired plasma membrane integrity, while a further increase electrolyte leakage. Damage to ultrastructure plasmalemma integrity had an inverse relationship with water content unfrozen positive frozen embryos. Changes activity of antioxidant enzymes differed cryopreservation. little effect on superoxide dismutase activity, although these treatments greatly reduced embryo viability. Activity dehydroascorbate reductase (DHAR) glutathione (GR) changed only slightly dehydration, but markedly decreased ascorbate peroxidase (APX) catalase (CAT). Freezing APX GR increased CAT dehydrated samples. A novel DHAR isozyme was induced the freeze-thaw cycle. Membrane lipid peroxidation detected control embryos, promoted by both freezing. The malondialdehyde (MDA) post-thaw maximum 30%. Thus, viability closely related damage not directly nor MDA accumulation.