Physiological and biochemical characteristics of cold stratification to overcome morphophysiological dormancy in Glehnia littoralis seed

Cold stratification is commonly used for breaking morphophysiological dormancy in Glehnia littoralis seeds. However, the physiological and biochemical characteristics of dormancy release are still unclear. For our study, dormant G. littoralis seeds were subjected to cold stratification (4°C). Physiological and biochemical characteristics, including germination percentage, the activities of antioxidant enzymes and α-amylase, and soluble sugar, soluble protein, H2O2, malondialdehyde (MDA) and coumarin were determined in imbibed seeds after different stratification periods (0, 30, 60, 90 or 120 days). The morphophysiological dormancy in G. littoralis seeds was completely released by cold stratification for 120 days. The activities of catalase (CAT) and content of hydrogen peroxide (H2O2) and total soluble sugars were significantly increased, while coumarins was significantly decreased during dormancy release. Dormancy release was significantly positively correlated with CAT activity (r = 0.903) and accumulation of H2O2 (r = 0.985) and total soluble sugars (r = 0.952), and significantly negatively correlated with coumarins (r = −0.919). Thus, the increase in H2O2, soluble sugars level and CAT activity and decrease in coumarins during cold stratification might contribute to promoting dormancy release in G. littoralis seeds.