聚乙二醇模拟干旱胁迫对兔儿伞生理特性的影响

Effects of Drought Stress Simulated by PEG-6000 on Physiological Characteristics of Syneilesis aconitifolia

以大庆市干旱草原移植的兔儿伞为试材,在室内模拟干旱条件下,研究了不同质量分数(10%、20%、30%)的聚乙二醇6000(PEG-6000)溶液对兔儿伞形态、叶片相对含水量、细胞膜透性、超氧化物歧化酶(SOD)活性的影响,以期评价兔儿伞的抗旱能力。结果表明:质量分数为10%、20%和30%的PEG-6000胁迫40h后,兔儿伞的形态均受到不同程度损害,质量分数为20%、30%的PEG-6000分别胁迫24、16h后,兔儿伞逐渐失去观赏价值;随着PEG-6000质量分数的增加和胁迫时间的延长,兔儿伞叶片相对含水量持续下降,复水后各处理均有7%～10%幅度的上升;细胞膜透性与胁迫程度呈极显著正相关,复水后各处理均有3%～7%幅度的上升;PEG-6000质量分数为10%、20%、30%处理的SOD活性在胁迫32、16、24h时达到最大值,说明兔儿伞在受到干旱胁迫伤害时,具有能有效清除超氧离子以抵御干旱胁迫的能力。

Taking Syneilesis aconitifolia transplanted from arid grassland habitats of Daqing as test materials,the influence of different mass concentrations（10%,20% and 30%） of PEG-6000 osmotic stress on S.aconitifolia＇s forms,leaf relative water content,membrane permeability and superoxide dismutase（SOD） activity under the condition of indoor simulation drought were studied in order to evaluate its drought resistance.The results showed that its forms were subject to varying damage after 40 h of the mass concentration of 10%,20% and 30% PEG-6000 stress,the ornamental value of S.aconitifolia began to disappeared gradually after 24 h and 16 h of PEG-6000 stress by 20% and 30% PEG-6000,respectively.With the concentration of PEG-6000 increasing and the time of stress prolonging,the leaf relative water content continued to decline,and then increased by 7%~10% after rewatering.It existed a very significant positive correlation between the membrane permeability and the level of stress,and then increased by 3%~7% after rewatering.The maximum value of SOD activity appeared at 32 h,16 h and 24 h of stress by 10%,20% and 30% PEG-6000,respectively,it showed that the protective enzyme system of S.aconitifolia could effectively remove uperoxides to resist the drought stress under drought stress damage.