Cryoprotectants and X-ray analysis on Passiflora seeds cryopreserved

The study aimed to evaluate the internal morphology of Passiflora eichleriana Mast., Passiflora nitida Kunth. and Passiflora mucronata Lam. seeds cryopreserved with different cryoprotectants. The treatment were control (without cryoprotectant or cryopreservation), seeds cryopreserved without cryoprotectant, 1.73, 2.28, 2.60 or 2.71 M glycerol, 0.37, 0.46, 0.54 or 0.61 M sucrose and 0.37, 0.72, 1.04 or 1.35 M dimethylsulfoxide. The seeds were cryopreserved in liquid nitrogen (-196 °C) for seven days. The cryopreserved seeds were dipped in water bath (37 °C) for 5 minutes to defrost. The percentage of filled, empty, malformed and damaged seeds was determined. The seeds were analyzed by X-ray to verify damages caused by the cryopreservation or defrost. Our results demonstrate that X-ray is an efficient method to analyses cryopreserved seeds and the cryopreservation technique did not cause mechanical damage of P. eichleriana, P. nitida and P. mucronata seeds.