A research on the technology of blackthorn (Prunus spinosa L.)

Blackthorn (BT, Prunus spinosa) is a thorny plant in the form of a high bush and its fruits are valuable for human health and wildlife. It contains plenty of vitamin C and beneficial antioxidants. BT is a useful plant species for afforestation and landscaping of marginal areas due to its tolerance to harsh ecological conditions. It is frequently encountered in destroyed areas, roadsides and ecotone zones. Despite its versatile benefits and wide natural distribution, studies on the seed technology of the species are quite limited. BT seeds have both seed bark and embryo-induced dormancy. This limits the seedling production of the species by seeds in nurseries. In this study, some morphological seed characteristics of BT seeds collected from Yığılca (Düzce) and Mengen (Bolu) provenances were determined first. Then, 13 different pre-treatments were applied to the seeds in order to remove the seed dormancy. Pre-treatments includes different combinations such as control, bark removal, stratification, GA3 treatment and sulfuric acid treatment. Pre-treated seeds were germinated in the laboratory at a constant 20°C and a variable temperature of 10/20°C (16/8 hours) and also sown in a greenhouse environment. Finally, untreated seeds were sown outdoors. There is no significant difference between the provenances in terms of morphological seed characteristics. According to laboratory results; while the effect of provenance on germination percentage (GP) was insignificant (p>0.05), the effect of pretreatment and germination temperature was significant (p<0.05). In addition, the effect of provenance x pre-treatment and pre-treatment x germination temperature interactions on GP is significant (p<0.05). Seeds germinated at a higher rate at variable germination temperature. The highest GP was achieved in the pre-treatment in which 100 ppm GA3 (Giberellic acid) was applied by removing the bark after 3 weeks of warm stratification. Greenhouse germinations were similar to laboratory germination results. BT seeds sown outdoors without pretreatment showed significant differences between provenances in terms of germination percentage.