二甲四氯胁迫对谷子幼苗叶片衰老特性和内源激素含量的影响  

Effect of MCPA on Leaf Senescence and Endogenous Hormones Content in Leaves of Foxtail Millet Seedlings

作　　者：郭美俊 白亚青 高鹏 申洁[1] 董淑琦[1] 原向阳[1] 郭平毅[1] GUO MeiJun;BAI YaQing;GAO Peng;SHEN Jie;DONG ShuQi;YUAN XiangYang;GUO PingYi(College of Agronomy,Shanxi Agricultural University/Laboratory of Crop Chemical Regulation and Chemical Weed Control,Taigu 030801,Shanxi)

机构地区：[1]山西农业大学农学院/作物化学调控实验室

出　　处：《中国农业科学》2020年第3期513-526,共14页Scientia Agricultura Sinica

基　　金：国家谷子高粱产业技术体系(CARS-06-13.5-A28);山西省重点研发项目(2015-TN-09);山西农业大学青年拔尖创新人才支持计划(TYIT201406)

摘　　要：【目的】研究除草剂二甲四氯对谷子叶片衰老特性以及叶片内源激素含量的影响,探讨谷子幼苗对二甲四氯胁迫的生理反应,为谷子抗除草剂胁迫机制及除草剂的安全使用提供理论依据。【方法】采用盆栽试验方法,选用晋谷21号和张杂10号为试验材料,设置二甲四氯剂量分别为0.75、1.50、3.00和6.00 kg·hm-2 4个水平。处理后5和15 d,测定谷子幼苗株高、叶面积、叶绿素含量、光合参数、叶绿素荧光参数、丙二醛(MDA)含量以及超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性和内源激素含量的变化,并分析了二甲四氯处理下谷子叶片中内源激素含量与光合特性参数、抗氧化酶活性间的相关性。【结果】与对照相比,喷施不同剂量二甲四氯均抑制了谷子的株高和光合作用,谷子叶片的叶绿素含量、净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、PSⅡ最大光化学效率(Fv/Fm)和电子传递速率(ETR)均出现不同程度降低;而非光化学猝灭(NPQ)的变化呈相反趋势。此外,二甲四氯对谷子植株光合特性的影响效应随着施药时间的延长逐渐减弱,表现为喷施除草剂15 d后,多数指标可恢复至对照水平。同时,不同剂量二甲四氯处理后均提高了谷子叶片SOD、POD、CAT活性及MDA含量,且随着施药时间的延长呈先升高后降低的趋势。二甲四氯胁迫提高了谷子叶片中脱落酸(ABA)和生长素(IAA)含量,降低了谷子叶片中赤霉素(GA)和玉米素(Zt)含量。ABA含量与叶绿素含量、Pn、Fo和ETR均表现为极显著负相关,与Gs显著负相关;除NPQ外,Zt含量与叶绿素含量和ETR均表现为极显著正相关,与Fo显著正相关。相关分析结果表明,叶片内源激素ABA含量与SOD、POD活性呈显著相关;IAA含量与CAT呈显著正相关;GA含量与POD活性呈显著相关。【结论】二甲四氯处理后,谷子通过提高内源激素Zt含量来降低ABA含量,一方面影响�【Objective】The objective of the experiment was to investigate the effect of MCPA on the senescence characteristics of leaves and contents of endogenous hormones in leaves of foxtail millet, and explore the physiological response of foxtail millet seedlings to MCPA stress, which provided a theoretical basis for the mechanism of herbicide resistance and the safe use of herbicide during cultivation.【Method】A pot-grown experiment was conducted with Jingu 21 and Zhangza10 as materials with four dosages(0.75, 1.50, 3.00, 6.00 kg·hm-2) of MCPA.After treatment for the 5 d and 15 d, the plant height, leaf area, chlorophyll content, photosynthetic parameters, chlorophyll fluorescence parameters, malondialdehyde(MDA) content, superoxide dismutase(SOD), peroxidase(POD), catalase(CAT) activity and endogenous hormone content of foxtail millet were determined.In addition, the correlation between endogenous hormone content and photosynthetic characteristics and antioxidant enzyme activity under MCPA stress were analyzed.【Result】Compared with the control, the chlorophyll content, net photosynthetic rate(Pn), transpiration rate(Tr), stomatal conductance(Gs), PSⅡ maximum photochemical efficiency(Fv/Fm), and electron transfer rate(ETR) in foxtail millet leaves were decreased with different MCPA dosages treatment;however, the change tendency of non-photochemical quenching(NPQ) is opposite.In addition, the effect of MCPA on the photosynthetic characteristics of foxtail millet gradually decreased with the extension of application time, which showed that most indexes could be restored to the control level after MCPA treatment 15 d.At the same time, SOD, POD, CAT activity and MDA content of foxtail millet leaves were increased with MCPA treatment at different dosages, which showed the trend of increasing first and then decreasing with the extension of application time.MCPA treatment increased abscisic acid(ABA) and auxin(IAA) content in foxtail millet leaves and decreased gibberellin(GA) and zeatin(Zt) content in foxtail m

关 键 词：谷子 二甲四氯 抗氧化酶 光合特性 内源激素 

分 类 号：S515[农业科学—作物学]