凹叶厚朴种子休眠与萌发特性的研究

Study on the Characteristics of Seed Dormancy and Germination of Magnolia biloba

用组织切片法对凹叶厚朴种子胚形态结构的观察、种皮透水性的测定、种子不同部位浸提液的生物测定,初步探讨了凹叶厚朴种子的休眠原因.结果表明:凹叶厚朴种子的胚已分化完全;内种皮有阻碍种子吸水的作用;外种皮和中种皮以及胚乳存在较多的发芽抑制物质.对凹叶厚朴种子的萌发试验表明,用1 500 mg/L赤霉素(GA3)浸种后低温层积处理是解除休眠、促进萌发的最佳方法,种子发芽率可达72%,比单独低温层积处理提高了17%.

Using the technique of tissue slicing,the experiment observed the morphology structure of embryo,measured the permeability of seed coat and the bioassay of the extract from different parts of Magnolia biloba seeds,and discussed the dormancy cause of Magnolia biloba seeds.The results show that the embryo is fully differentiated,the water absorptivity of seed is impeded by endopleura,and there exist more inhibitors in the endosperm,episperm and mesosperm of seeds.The results of germination experiment on Magnolia biloba seeds show that treating the seeds of Magnolia biloba with cold stratification after immersing into 1 500 mg/L GA3 is the optimal method to break dormancy and promote germination,which can obtain 72% germination,and increase 17% compared to the seeds treated only with cold stratification.