Stratification for Breaking Morphophysiological Dormancy in Corydalis platycarpa (Maxim. ex Palib.) Makino Seeds: Requirements Embryo Growth and Germination

Corydalis platycarpa (Maxim.ex Palib.)Makino contains various alkaloids with notable clinical therapeutic value, including inhibiting gastric juice secretion and acting as an analgesic.It serves as an antibacterial agent.However, information on the germination and dormancy of C. platycarpa for ecosystem restoration and species utilization is lacking.Therefore, this study aimed to classify dormancy types and improve dormancy-breaking methods through the effects of phenology, move-along, plant growth regulators, and stratification at various temperatures on C. platycarpa seeds.Fresh seeds of C. platycarpa showed underdeveloped embryos and did not germinate within 4 weeks at any temperature, confirming morphophysiological dormancy (MPD).Germination of 53.0% was observed after 12 weeks at 4C but the remaining ungerminated seeds required warm temperatures before low temperatures for embryo growth and germination, evidenced in phenology and move-along experiments.However, GA 3 did not replace cold or warm stratification and did not affect germination.Therefore, C. platycarpa seeds were classified as having two MPD levels, with 45.0% and 55.0% being non-deep and deep complex MPD levels, respectively.While dormancy in C. platycarpa seeds took a long time to break in the natural environment, it was efficiently broken by 4 weeks of stratification at 15/6C before experiencing low temperatures.This research on classifying dormancy and improving dormancy-breaking methods can be used for large-scale propagation for ecosystem restoration and species utilization.