快速脱水对后熟黄连种子萌发及生理生化的影响

Effect of Rapid Dehydration on Germination and Physiological and Biochemical Characteristics of the Ripened Seeds of Coptis chinensis

目的:探究脱水对黄连种子萌发及生理生化指标的影响,初步揭示其脱水耐性的内在机理。方法:设置30℃、40℃、50℃、60℃温度对种子进行脱水处理,分别测定生活力、发芽率与电导率。选择快速脱水(60℃)获得不同含水梯度种子,测定其可溶性糖(SS)、可溶性蛋白(SP)、丙二醛(MDA)的含量以及抗氧化酶系统(POD、SOD、CAT)活性。应用相关性分析和双标图进行数据分析以探索在不同含水量下各指标的变化关系。结果:随着含水量降低,种子生活力与发芽率均降低,电导率升高;SS、SP、POD与SOD显著升高;CAT与MDA显著降低。SS与SP、POD、SOD呈极显著正相关,与MDA、CAT呈极显著负相关。结论:黄连种子不耐脱水,种子内各生理生化指标之间可能存在协同或拮抗机制以发挥保护作用,后期脱水伤害大于保护作用是种子失活的主要原因。

Objective:To explore the influence of dehydration on seed germination and physiological and biochemical indexes of Coptis chinensis,and to preliminarily reveal the internal mechanism of desiccation endurance.Methods:Seeds were dehydrated under 30℃,40℃,50℃and 60℃,and theviability,germination rate and conductivity were determined,respectively.Rapid dehydration at 60℃was selected to obtain seeds with different water contents and the contents of soluble sugar(SS),soluble protein(SP),malondialdehyde(MDA)and the activities of antioxidant enzyme system(POD,SOD,CAT)were measured.The correlation analysis and biplot were applied to analysis data and explore the change relation of all indexes under different water contents.Results:With water contents reduced,the viability and germination rate of seeds were declined while the conductivity increased;SS,SP,POD and SOD significantly increased while CAT and MDA significantly decreased.SS was very significantly correlated with SP,POD and SOD,but it has a significantly negative correlation with MDA and CAT.Conclusion:Coptis chinensis seeds are not resistant to dehydration,and different physiological and biochemical indexes work cooperatively or antagonistically with each other to protect the viability of seeds.The main reason for deactivation is that the damage of dehydration is greater than the protective effect.