Evaluation of analytical techniques to predict viability after cryopreservation

Preservation of plant germplasm is important to safeguard biodiversity and to store elite plants. Cryopreservation is one of the possible preservation techniques. Research for a cryopreservation protocol is often inefficient because of slow or poor regrowth of plant material. Therefore, at least one technique, that allows a quick and accurate prognosis of viability after cryopreservation, is required. We evaluated five techniques: electrolyte leakage, triphenyltetrazoliumchloride ( TTC) staining ( visual and spectrophotometrical analysis), malondialdehyde concentrations in plant tissue and a mathematical model that relates 'water content' to the weight of encapsulated plant material. Electrolyte leakage and TTC-staining ( if visually analysed) are efficient to predict viability. Our mathematical model allows us to save time and plant material in order to develop an efficient encapsulation - dehydration protocol. All other techniques were rejected because of the high variability of the results. This is due to the variability of biochemical activity in plant tissue and the small amount of tissue used in the experiments.