干旱胁迫下外源褪黑素对黄瓜叶片生理特性的调控效应  

Regulation Effect of Exogenous Melatonin on Physiological Characteristics of Cucumber Leaves under Drought Stress

作　　者：张盼盼[1] 王小艳 陈怡佳 李昊 魏骞 ZHANG Pan-pan;WANG Xiao-yan;CHEN Yi-jia;LI Hao;WEI Qian(School of Life Sciences,Yulin University,Yulin 719000,China)

机构地区：[1]榆林学院生命科学学院,陕西榆林719000

出　　处：《榆林学院学报》2023年第5期27-32,共6页Journal of Yulin University

基　　金：国家自然科学基金项目(31860340);陕西省小杂粮现代农业产业技术体系项目(NYKJ-2022YL(XN)28);榆林市科技局科技计划项目(CXY-2022-69)资助。

摘　　要：为探究褪黑素(MT)对干旱胁迫下黄瓜叶片生理特性的调控机理,以“亨优小菜园”黄瓜品种为供试材料,采用土培方式,20%的PEG-6000连续灌根2 d模拟干旱胁迫,设置4种叶面喷施不同浓度MT处理,分别为50μmol·L^(-1)、100μmol·L^(-1)、150μmol·L^(-1)、200μmol·L^(-1),以喷施等量清水作为对照,研究了干旱胁迫下褪黑素对黄瓜幼苗生理特性的影响。结果表明:(1)喷施MT溶液促进了干旱胁迫下黄瓜幼苗株高、单株绿叶面积、叶柄干重、叶片干重和茎干重的增加,其中100μmol·L^(-1)MT处理促进效果最佳,其指标分别比对照提高了55.2%、54.5%、60.3%、55.7%和95.9%;(2)在干旱胁迫环境下,经过喷施MT溶液处理的黄瓜幼苗叶片过氧化物酶(POD)活性、超氧化物歧化酶(SOD)活性和可溶性蛋白含量增强,丙二醛(MDA)含量下降。150μmol·L^(-1)MT对黄瓜幼苗POD活性促进效果最大;100μmol·L^(-1)MT对黄瓜幼苗SOD活性和可溶性蛋白含量促进效果最大,并且对黄瓜幼苗MDA含量降低效果最为明显;(3)MT溶液增加了干旱胁迫下黄瓜幼苗光系统的光化学淬灭系数、非光化学淬灭系数、最大光化学效率和实际光能利用率。处理后6 d,100μmol·L^(-1)MT促进效果最佳,其指标分别比对照提高了15.9%、65.4%、5.3%和6.9%。由此可见,在干旱胁迫下,喷施浓度在100μmol·L^(-1)~150μmol·L^(-1)之间的MT溶液可以促进黄瓜幼苗地上部形态的发育,提高幼苗叶片的光合作用,增强叶片中抗氧化物酶的活性,减缓了干旱胁迫对黄瓜幼苗的膜脂过氧化作用,从而有效缓解了干旱胁迫对黄瓜幼苗的危害。To investigate the regulation mechanism of melatonin(MT)on the physiological characteristics of cucumber leaves under drought stress,the physiological characteristics of cucumber seedlings under different concentrations of melatonin treatment(0μmol·L^(-1),50μmol·L^(-1),100μmol·L^(-1),150μmol·L^(-1)and 200μmol·L^(-1)respectively)are investigated by simulating drought stress with 20%PEG-6000 in soil culture using“Hengyou Garden”cucumber variety as the test material.The results show that(1)spraying MT solution promotes the increase of cucumber seedling height,single green leaf area,petiole dry weight,leaf dry weight and stem dry weight under drought stress,and the best effect is achieved when the concentration of MT solution is 100μmol·L^(-1),and its indexes increase by 55.2%,54.5%,60.3%,55.7%and 95.9%,respectively,compared with the control;(2)Under the drought stress environment,the peroxidase(POD)activity,superoxide dismutase(SOD)activity and soluble protein content of cucumber seedling leaves treated with MT solution spray are enhanced,and the malondialdehyde(MDA)content decrease.150μmol·L^(-1)MT has the best promoting effect on POD activity of cucumber seedlings.The promoting effect of 100μmol·L^(-1)MT on SOD activity and soluble protein content of cucumber seedlings is the greatest,and the reducing effect on MDA content of cucumber seedlings is the greatest.(3)Spraying MT solution increase the photochemical quenching coefficient,non-photochemical quenching coefficient,maximum photochemical efficiency and light energy utilization of the photosystem of cucumber seedlings under drought stress.The best effect is achieved when the MT solution concentration is 100μmol·L^(-1),and its indexes increase by 15.9%,65.4%,5.3%and 6.9%,respectively,compared with the control.It can be seen that under drought stress,spraying MT solutions with concentrations between 100μmol·L^(-1)and 150μmol·L^(-1)can promote the development of aboveground morphology of cucumber seedlings,improve photosynthesis in seedl

关 键 词：褪黑素 黄瓜 干旱胁迫 生理特性 

分 类 号：S642.3[农业科学—蔬菜学]