The Researches on Some Seed Characteristics of Magnolia grandiflora L. and Magnolia x soulangiana Soul

Seed morphology, maturation, dormancy and seed vigor (direct or indirect) were studied in a series of laboratory experiments for Magnolia grandiflora L. and Magnolia x soulangiana Soul. Both Magnolia species exhibit seed dormancy, requiring pretreatments including cold stratification (classical stratification), prechilling, osmotic conditioning and a treatment combination of cold stratification + gibberellic asit (GA(3)) hormone were employed to eliminate seed dormancy for both species. At the end of the experiment naked stratification and osmotic conditioning did not sufficiently break seed dormancy for both species. However, cold stratification and the cold stratification + hormone treatment combination enhaced seed germination for tree species.