Cryopreservation of Prunus padus seeds: emphasising the significance of Bayesian methods for data analysis

Abstract

Conservation of Prunus padus L., a tree of high ecological and pharmacological importance, has been evaluated by storing seeds at subzero (−20 °C and −80 °C) and cryogenic (−196 °C) temperatures for various durations. The effect of the seed’s water content (WC) ranging from 3.5% to 21.1%, fresh weight basis, and the effect of cooling and rewarming procedures on seed viability was investigated. Emergence of seedlings was observed for 40%–55% of the noncryopreserved seeds, with no significant effect of WC. The same seedling emergence was recorded for seeds cryopreserved by direct immersion in liquid nitrogen within the WC range of 3.5%–15.0%. Seeds rehydrated above 17% WC were unable to tolerate cryopreservation. Seedling emergence was not affected by cooling regime but decreased by 10% after stepwise rewarming compared with rapid rewarming in a water bath or on air. No reduction in seedling emergence was recorded after storage at −20 °C, −80 °C, and −196 °C for 1 h, 1 week, and 1 month. We recommend seed storage at subzero or cryogenic temperatures as an effective conservation option for P. padus and possibly other Prunus species. We also demonstrated high effectiveness and reliability of Bayesian statistical methods for analyzing binomial data such as the data obtained in seed conservation experiments.