毛果含笑种子休眠的原因及其休眠的破除

Caused of Seed Dormancy and Dormancy Breaking of Michelia sphaerantha

毛果含笑为分布于云南的珍贵绿化观赏树种,其种子具有休眠习性。为解决毛果含笑种子的有效繁殖问题,从种子的形态结构,种皮的透水性、种子中的萌发抑制物质测定,种子的生活力测定及其种子萌发试验等方面,对毛果含笑种子休眠的原因及破除方法进行了研究。结果表明:种胚发育不完全和种子所含的萌发抑制物质是导致毛果含笑种子休眠的主要原因。毛果含笑种皮具有较好的透水性,与其休眠的关系不大,由此可认为毛果含笑种子的休眠类型为形态生理休眠;用蒸馏水浸泡或赤霉素液浸泡种子均可有效破除毛果含笑种子休眠,促进其萌发。

Michelia sphaerantha is a rare ornamental tree species distributed in Yunnan province characterized by seed dormancy.In order to promote the propagation of M.sphaerantha,the causes of seed dormancy and the methods for breaking dormancy were studied from the morphological structure,the water permeability of seed coat,inhibitory substances in seed,seed vitality determination and seed germination test.The study results showed that incomplete development of embryos and inhibitory substance in seed were two main reasons for seed dormancy.The water permeability of M.sphaerantha is good,implied the low correlation with seed dormancy.It was therefore conclude that the seed dormancy of M.sphaerantha is morphological and physiological dormancy.Soaking seeds with distilled water or gibberellic acid solution could effectively break the dormancy of M.sphaerantha seeds.