综合处理措施对解除青钱柳种子休眠的影响

Effects of comprehensive treatments on breaking dormancy of Cyclocarya paliurus seeds

研究了综合处理措施对青钱柳种壳结构和透性的影响,并对休眠解除过程的果皮浸提液进行了生物测定。结果表明:浓硫酸处理可在一定程度上破坏青钱柳种子木质坚硬的种壳结构;在酸蚀处理基础上再进行GA3浸泡和GA3拌沙层积处理,随着层积时间的延长,种壳表面出现孔洞且逐渐变大,种胚含水量和种子呼吸速率显著提高,果皮浸提液抑制作用显著降低,裂口萌动种子中可能具抑制作用的物质种类减少。说明综合层积处理能有效破坏青钱柳种子坚硬的种壳结构,改善种皮透性,促进果皮中抑制物质的降解,从而加速种子休眠的解除。

Cyclocarya paliurus seeds remain deep dormancy characteristics, and the seeds usually take two years to germinate in natural condition. The effects of comprehensive treatments to the structure and permeability of husk were studied, and the bioassays of the pericarp extract during breaking dormancy were measured. The results show that the chemical scarification with concentrated sulphuric acid （H2504） could destroy the hard structure of husk to a certain extent, therefore could alleviate the mechanical and permeability barriers; after chemical scarification, the seeds were soaked in gibberellic acid （GA3） and then stratified in the sand moistened with GA3; while the stratification time of comprehensive treatments was prolonged, some pores appeared in the surface of husk and gradually became larger; meanwhile, the water content on embryo and seed respiratory were significantly enhanced, however the inhibitory effects of pericarp extract were significantly reduced. The Gas Chromatography-Mass Spectrometry （GC-MS） identification results for methanol extract from pericarp showed that there were fewer potential inhibitors in the germinating seeds than those in the untreated seeds. In conclusion, the comprehensive treatments combined with chemical scarification, exogenous application of GA3 and stratification could destroy the hard structure of husk, promote the exchange of gas and water, and accelerate the degradation of inhibitors, therefore it could alleviate dormancy of C. parliurus seeds in a relatively short period of time.