Dormancy-break and germination in seeds of Prunus campanulata (Rosaceae) --Effect of stratification on germinaiton

Intact seeds (seed endocarp) from freshly harvested fruits of Prunus campanulata were dormant, and required 4C 6 weeks of warm followed by 8 weeks of cold stratification for maximum germination percentage. Removing both endocarp and seed coat, however, promoted germination in a high percentage of non-stratified seeds. Treatment of intact, nonstratified seeds with gibberellic acid (GA3) was only partially effective in breaking dormancy. However, GA3 promoted germination of non-stratified seeds in which the endocarp (but not the seed coat) had been removed. Thus, dormancy in P. campanulata seeds is imposed by the covering layers. Dormancy break is accompanied by a decrease in ABA content of the covering layers and germination by an increase of embryonic GA4 content.