Annual dormancy cycle and influence of flooding in buried seeds of mudflat populations of the summer annualLeucospora multifida

Abstract

AbstractDormant seeds of Leucospora multifida (Michx) Nutt. were used to determine: (1) temperature requirements for loss of dormancy; (2) if buried seeds undergo seasonal changes in their dormancy states; and (3) effects of flooding on dormancy loss and induction. Seeds came out of dormancy when buried at 5°C and 15/6°C for 12 weeks, but at 20/10°C, 25/15°C and 30/15°C, they gained the ability to germinate only at 30/15°C and 35/20°C. Seeds buried in soil and exposed to natural seasonal temperature changes under non-flooded conditions exhibited an annual conditional dormancy/non-dormancy cycle, being non-dormant in spring and early summer, and conditionally dormant in late summer and autumn. Non-dormant seeds required light for germination at all thermoperiods, and they did not germinate in light or darkness at 15/6°C. Flooding prevented non-dormant seeds from entering conditional dormancy in summer, and it prevented dormant seeds from coming out of dormancy in winter. However, if dormancy loss had start...