Effect of Pretreatments on Seed Germination of Prunus mahaleb L.

Sexual propagation of Prunus mahaleb is difficult due to seed dormancy. To overcome dormancy and maximize germination, various pretreatments have been applied, including stratification (warm and cold), gibberellic acid (GA3), sulfuric acid scarification (AS), and endocarp removal. The results show that warm stratification (WS) prior to cold stratification (CS) does not improve seed germination and a long period of WS (3 months) is disastrous for germination. CS alone (up to 4 months) has been found to hasten and increase seed germination. Pretreatment of the seeds with exogenous GA3, during the CS period, has been observed to result in significantly higher seed germination. AS of seeds for 45 minutes prior to GA3 (1000 ppm for 24 hours) plus CS (up to 1 month) pretreatment has been considered to reduce the mechanical resistance of endocarp and improve germination. However, extended time of AS (180 minutes) prior to GA3 plus CS pretreatment has been found to harm the seeds. The removal of endocarp has been noted to significantly improve germination. Seeds without endocarp, which were pretreated with GA3 (1000 or 2000 ppm for 24 hours) and then cold stratified for 1 month, have been noted to exhibit the highest germination percentages.