Dormancy phases in seeds ofVerbascum thapsus L.

Summary Seeds ofVerbascum thapsus were imbibed on filter papers in Petri dishes and were exposed to a series of temperatures of 4°C10°C20°C10°C4°C in darkness. After each temperature treatment lasting one month, samples were removed and tested in light and darkness over a range of alternating temperatures. The results showed us that the dormancy state changes gradually according to the imbibition temperatures simulating the seasonal cycle. The ecological implications of the dormancy phases for the regulation of germination in natural conditions are discussed.