下延叶古当归种子休眠特性与解除方法

Dormancy characteristics and breaking methods of Archangelica decurrens seeds

【目的】研究下延叶古当归(Archangelica decurrens Ledeb.)种子休眠特性并找到解除休眠的方法,为该物种种质资源保护和开发利用提供科学依据。【方法】以下延叶古当归野生种子为材料,通过室内控制实验法对果实和种子基本生物学特性、种子萌发抑制物质进行研究,分析低温层积处理以及赤霉素不同浓度和时间交互处理对其萌发率、萌发势、萌发指数的影响。【结果】种皮不阻碍种子吸水;种子粉末浸取液对白菜(Brassica pekinensis)种子萌发及幼苗生长具有显著抑制作用;30~50 d低温层积处理能极显著提高下延叶古当归种子萌发率;果实形态成熟时种胚发育不完全,低温层积能促进种胚发育;使用3000mg/L赤霉素浸种24 h可使种子萌发率显著提升至72.00%。【结论】下延叶古当归种子休眠是由种子内萌发抑制物和种胚发育不完全共同作用引起的形态生理休眠,播种前将种子低温层积30~50 d,或使用2000~4000 mg/L浓度的赤霉素浸种24 h可有效解除种子休眠从而促进种子萌发。

【Objective】The research aimed to explore the seed dormancy characteristics of Archangelica decurrens Ledeb.and find out the method of breaking dormancy,so as to provide scientific basis for the protection,development and utilization of germplasm resources of this species.【Methods】With wild seeds of A.decurrens as research materials,the basic biological characteristics of fruits and seeds and seed germination inhibitors were studied by laboratory control experiments,and the effects of cold stratification treatment and gibberellin treatment with different concentrations and time on the germination rate,germination potential and germination index of seeds were analyzed.【Results】The seed coat did not hinder the water absorption of the seeds;the seed powder extract had a significant inhibitory effect on the seed germination and seedling growth of Brassica pekinensis;30-50 d cold stratification treatment could significantly improve the seed germination rate of A.decurrens;seed embryo development was incomplete when fruit morphologically matured,and cold stratification could promote seed embryo development;seed soaking with 3,000 mg/L gibberellin for 24 h could significantly increase the seed germination rate to 72.00%.【Conclusion】The seed dormancy of A.decurrens is the morphophysiological dormancy caused by the combined action of germination inhibitor in the seed and incomplete embryo development.The seeds were cold stratified for 30-50 d before sowing or using 2000-4000 mg/L gibberellin soaking the seeds for 24 h can effectively break seed dormancy and promote seed germination.