Effect of different conditions of storage on seed viability and seedling growth of six European wild fruit woody plants

Abstract

Key messageMalus sylvestris(L.) Mill.,Pyrus communis(L.),Sorbus aucuparia(L.),Prunus avium(L.),Prunus padus(L.), andCornus sanguinea(L.) are related, co-occurring species producingorthodoxseeds. However, we observed differences in their response to storage conditions, such as storage at different seed moisture contents (5%, 8%, and 11%) and/or temperatures (− 3 °C, − 18 °C, and − 196 °C). Severe desiccation to ca. 5% of MC negatively affected seeds ofM. sylvestris. Seeds ofP. aviumwere sensitive to storage in LN or at − 18 °C.S. aucupariaseeds are best stored at − 3 °C, whereasC. sanguineaseeds tolerate desiccation and storage in LN. In general, species with deeper physiological dormancy (S. aucuparia,P. padus, andC. sanguinea) tended to be more tolerant to desiccation and low temperatures. For all species, storage conditions did not affect seedling growth.ContextWild fruit woody species face many threats such as genetic loss, population fragmentation, and alien species; thus, their genetic variability should be preserved.AimsTo examine the effect of storage conditions on seed viability and the initial growth of seedlings of six European wild fruit species: Malus sylvestris (L.) Mill., Pyrus communis (L.), Sorbus aucuparia (L.), Prunus avium (L.), Prunus padus (L.), and Cornus sanguinea (L.).MethodsSeeds were desiccated to three different levels of moisture content (ca. 5, 8, or 11%) and stored at three different temperatures (− 3°, − 18°, or − 196 °C; liquid nitrogen, LN) for up to 3 years. Germination and seedling emergence tests were performed as well as measurement of seedling growth.ResultsDesiccation of M. sylvestris seeds from 10.7 to 4.9% significantly lowered germination from 91 to 77% and seedling emergence from 88 to 74%. In P. avium, LN storage significantly inhibited seedling emergence, both in the laboratory and the greenhouse, but did not affect total seed germination. In P. communis, P. padus, and C. sanguinea, neither germination nor seedling emergence was affected by seed storage conditions. There were small or no differences in stem height and root collar diameter in the first year of seedling growth of stored seeds.ConclusionSpecies with deeper physiological dormancy (S. aucuparia, P. padus, C. sanguinea) tended to be more tolerant of various storage conditions. Seeds of P. padus and C. sanguinea can be stored long term at − 18 °C or in LN at 5–8% MC without losing viability. M. sylvestris and P. avium seeds are sensitive to desiccation below 6% MC or low temperature of storage at − 18 °C or − 196 °C, respectively. We observed that storage conditions had significant influence on germination and seedling emergence but had no effect on seedling growth after the first growing season.