中文摘要：

以干旱半干旱地区分布的乌拉尔甘草、光果甘草为研究对象,系统的研究了增强UV-B辐射对2种甘草种子萌发特性、幼苗形态和生物量的影响及种子萌发第1、3、5、7天时过氧化氢酶（CAT）活性的变化。结果表明：增强UV-B辐射对2种甘草种子最终发芽率、发芽势和发芽指数并无显著影响;增强UV-B辐射极显著抑制2种甘草种子萌发期间胚根和下胚轴伸长,降低2种甘草幼苗生物量且致使幼苗下胚轴及胚根外部颜色明显发生变化,呈黄褐色;增强UV-B辐射处理初期,2个品种甘草CAT酶活性均显著高于对照,随着处理天数的增加,CAT酶活性开始下降。因此认为：增强UV-B辐射处理后,能启动甘草幼苗体内的抗氧化防御系统,但最终仍导致甘草幼苗体内活性氧代谢紊乱,可能对甘草细胞膜系统造成伤害,出现膜脂过氧化。

英文摘要：

Effect of enhanced UV-B radiation on seed germination property,seedling morphology,biomass and the change of catalase（CAT） activity when the seed germinated at 1 day,3 days,5 days,7 days respectively of Glycyrrhiza uralensis and Glycyrrhiza glabra which were distributed in arid-semiarid region have been studied.The results showed： the effect of enhanced UV-B radiation on the seed germination percentage,germination energy and germination index of the two types seed were not significant;enhanced UV-B radiation could significantly inhibit the elongation,decrease the biomass and cause the external color significantly became brown of radicle and hypocotyl of the two types seed during germination;At early period of treatment,CAT activity of the two types seed were significantly higher than control,but with the treatment time increased,CAT activity decreased.Therefore,the author considered that the UV-B radiation treatment could start the antioxidant defense system of Glycyrrhizic seedling,but finally it still could result in disorder of the ROS metabolism and probably do great harm to the membrane system.At the end,membrane lipid peroxidation appeared.