GA和ABA调控人参种子休眠的生理机制

Physiological Mechanism of GA and ABA Regulating Ginseng Seed Dormancy

人参(Panax ginseng C.A.Meyer)是五加科(Araliaceae)多年生草本植物,依靠种子繁殖,但其具有的形态和生理双重休眠的特性给人参生产带来不便。因此解析人参种子休眠的生理机制,快速解除人参种子休眠至关重要。本研究以完成形态后熟的人参种子为材料,研究人参种子生理后熟过程中的发芽率、可溶性糖含量、淀粉酶活性和激素含量的动态变化。通过施加外源GA_(3)和去除胚乳实验,考察GA_(3)和ABA对人参种子生理后熟的影响。结果表明,(1)人参的生理休眠会随着冷层积时间的增加而解除,在休眠解除过程中可溶性糖含量、α-淀粉酶活性和β-淀粉酶活性都呈上升趋势,第6时期,胚乳中可溶性糖含量为第1时期的1.74倍,α-淀粉酶活性和β-淀粉酶活性分别为第1时期的2.16倍和2.86倍;(2)冷层积过程中,胚和胚乳中ABA含量呈下降趋势,与第1时期相比,第6时期胚中下降76.63%,胚乳中下降88.42%;(3)冷层积过程中,GA在胚和胚乳中呈上升趋势,第6时期时,胚乳中增加至第1时期的1.95倍,胚中增加至第1时期的9.82倍,并且观察到在第5时期开始明显上升;(4)施加外源GA_(3)可以明显促进人参种子生理休眠的打破,发芽率较对照组提升52.53%;(5)去除胚乳可以解除胚乳对胚的抑制,从而解除胚的休眠,促进胚萌发。本研究可为人参种子后熟过程中休眠解除机制的研究提供参考依据。

Ginseng(Panax ginseng C.A.Meyer)is a perennial herbaceous plant of the Araliaceae family.It relies on seeds for reproduction,but its morphological and physiological double dormancy characteristics bring inconvenience to ginseng production.Therefore,it is very important to analyze the physiological mechanism of ginseng seed dormancy and quickly release ginseng seed dormancy.This report uses the mature ginseng seeds as materials to study the dynamic changes of the germination rate,soluble sugar content,amylase activity and hormone content during the physiological after-ripening process of ginseng seeds.Through the experiment of applying exogenous GA_(3)and removing the endosperm,the effects of GA_(3)and ABA on the physiological after-ripening of ginseng seeds were investigated.The result shows,(1)The physiological dormancy of ginseng will be released with the increase of cold stratification time.During the dormancy release process,the soluble sugar content,α-amylase activity andβ-amylase activity will all increase.In the 6th stage endosperm,the soluble sugar content was 1.74 times that of the 1st stage,and theα-amylase activity andβ-amylase activity were 2.16 times and 2.86 times that of the 1st stage,respectively;(2)During the cold stratification process,the ABA content in the embryo and endosperm showed a downward trend.Compared with the 1st stage,the embryo in the sixth stage decreased by 76.63%,and the endosperm decreased by 88.42%;(3)During the cold stratification process,GA showed an upward trend in embryo and endosperm.In the 6th stage,the endosperm increased to 1.95 times of the 1st stage,and the embryo increased to 9.82 times of the first stage.The 5th period began to rise significantly;(4)The application ofexogenous GA_(3)can obviously promote the break of the physiological dormancy of ginseng seeds,and the germination rate is increased by 52.53%compared with the control group;(5)Removal of endosperm can relieve the inhibition of the endosperm on the embryo,thereby releasing the dormancy of the embryo and promoting the germination of the embryo.This study can provide a reference for the study of the mechanism of release of dormancy during the ripening process of ginseng seeds.