PEG-6000模拟干旱胁迫对糯高粱幼苗生理特性的影响

Effects of PEG-6000 Simulated Drought Stress on Physiological Characteristics of Glutinous Sorghum Seedlings

为了明确干旱胁迫下糯高粱幼苗的抗旱性及其对干旱的生理响应机制,并筛选出抗旱性较强的品种,以22个糯高粱品种为材料,利用聚乙二醇(PEG-6000)模拟干旱胁迫,对干旱胁迫下不同品种糯高粱幼苗的生长情况、抗旱性进行比较,并分析相关生理指标的变化。结果表明:与对照相比,干旱胁迫下糯高粱幼苗的株高、根长、苗鲜质量、叶片相对含水量和叶绿素含量均不同程度降低。根据抗旱性综合度量值(D值)对糯高粱苗期抗旱性进行评价,将22个糯高粱品种分为3类,其中抗旱型品种8个,中间型品种11个,干旱敏感型品种3个。干旱胁迫下糯高粱幼苗的脯氨酸含量、丙二醛含量以及超氧化物歧化酶(SOD)和过氧化物酶(POD)活性均较对照有所提高,抗旱能力较强的糯高粱品种脯氨酸积累量较高、丙二醛的增加量较低,而SOD和POD均保持较高的水平。综合分析,M13抗旱性最好。

In order to clarify the drought resistance of glutinous sorghum seedlings under drought stress and its physiological response mechanism to drought,and to screen for more resistant varieties,22 sorghum varieties were used as materials to simulate drought stress by using polyethylene glycol(PEG-6000),to compare the growth of glutinous sorghum seedlings from different varieties under drought stress,drought resistance,and to analyze the changes of relevant physiological indexes.The results showed that the plant height,root length,seedling fresh mass,leaf relative water content and chlorophyll content of glutinous sorghum seedlings were reduced to different degrees under drought stress compared with the control.The 22 glutinous sorghum varieties were classified into three categories,including eight drought-resistant varieties,11 intermediate varieties,and three drought-sensitive varieties,based on the comprehensive drought tolerance measure(Dvalue)for evaluating drought tolerance in the seedling stage of glutinous sorghum.The proline content,malondialdehyde content and the activities of superoxide dismutase(SOD)andperoxidase(POD)of glutinous sorghum seedlings increased under drought stress compared with the control,and the drought-resistant glutinous sorghum varieties had higher proline accumulation and lower malondialdehyde increase,while SOD and POD were maintained at higher levels.In a comprehensive analysis,M13 had the best drought tolerance.