Seed Dormancy Class and Germination Characteristics of Prunus maackii and P. virginiana

Prunus species exhibit physiological dormancy (PD), requiring dormancy-breaking treatments for successful germination in horticultural and ecological applications. Although stratification, gibberellic acid (GA 3 ) application, and endocarp removal are commonly used, their effectiveness varies by species and dormancy depth. Despite the ornamental and ecological value of Prunus maackii and P. virginiana , their dormancy characteristics remain poorly understood. This study evaluated seed dormancy characteristics and effective germination treatments for both species. Seeds and stones were exposed to four alternating temperature regimes, seven stratification treatments, four GA 3 concentrations with or without endocarp removal, and combined GA 3 and stratification treatments. Water imbibition tests indicated that both species lack physical dormancy (PY), and fully developed embryos excluded morphological dormancy (MD). In P. maackii , the highest germination rate (65.6%) was achieved through a warm and cold stratification regime consisting of 30 days at 20 °C followed by 60 days at 4 °C. In P. virginiana , the highest germination rate (70.8%) was achieved with warm and cold stratification (30 days at 20 °C followed by 90 days at 4 °C) combined with 1000 mg·L −1 GA 3 . Based on their responses to stratification and GA 3 treatment, P. virginiana was classified as having intermediate PD. In comparison, P. maackii exhibited characteristics of both nondeep and intermediate PD, indicating the presence of interspecific variation in dormancy types between the two species. These results provide species-specific protocols for improving the propagation efficiency of underutilized Prunus species.