Effects of seed moisture content, warm, chilling, and exogenous hormone treatments and germination temperature on the germination of blackthorn seeds

Blackthorn (Prunus spinosa L.) germination is often low, so new methods need to be developed with a view to improving nursery yields and to inform decision-making on natural regeneration. To this end, the effects of seed moisture content (MC) levels in combination with warm and chilling treatments on blackthorn seed dormancy release were investigated. In another experiment, the effect on seed germination of warm and chilling treatments in combination with exogenous hormones was investigated. Following treatment, the seeds were allowed to germinate at a constant 15 degrees C with 8h lighting per day or 20 (dark)/30 degrees C (light). Seed lot effects were evident, but were consistent across treatments. Seeds adjusted to the lower target MC level (TMC) maintained high germination potential over a longer period of treatment than in those held in the fully imbibed (FI) state. The highest germination was achieved in the TMC seeds that were given six weeks warm treatment followed by 32weeks chilling. Hormone treatments significantly reduced the amount of chilling needed to release dormancy in TMC seeds, but not in the FI seeds. Overall, germination response was better at 15 degrees C test temperature than at 20/30 degrees C.