干旱胁迫条件下外源褪黑素提高小麦穗花发育和穗粒数的机理  

Mechanism of exogenous melatonin improving the development of spike and floret and grain numbers per spike in wheat under drought stress

作　　者：王璐媛 刘淋茹 袁鑫茹 张艳艳 张荣 段剑钊 贺利 冯伟[1,2,3] 王志强 王永华[1,2] 郭天财[1,2] WANG Lu-yuan;LIU Lin-ru;YUAN Xin-ru;ZHANG Yan-yan;ZHANG Rong;DUAN Jian-zhao;HE Li;FENG Wei;WANG Zhi-qiang;WANG Yong-hua;GUO Tian-cai(College of Agronomy,Henan Agricultural University,Zhengzhou,Henan 450046,China;National Engineering Research Center for Wheat,Zhengzhou,Henan 450046,China;Key Laboratory of Regulating and Controlling Crop Growth and Development,Ministry of Education,Zhengzhou,Henan 450046,China)

机构地区：[1]河南农业大学农学院,河南郑州450046 [2]国家小麦工程技术研究中心,河南郑州450046 [3]教育部作物生长发育调控重点实验室,河南郑州450046

出　　处：《植物营养与肥料学报》2024年第8期1477-1489,共13页Journal of Plant Nutrition and Fertilizers

基　　金：国家自然科学基金项目(32101830);国家重点研发计划项目(2023YFD2300204);财政部和农业农村部—国家现代农业产业技术体系建设专项(CARS-03)。

摘　　要：【目的】探究外源褪黑素(melatonin,MT)对水分胁迫下小麦穗花发育及抗氧化能力的调控效应,为采用化控方法有效缓解干旱胁迫对小麦的危害提供技术支撑。【方法】以多穗型品种‘豫麦49-198’和大穗型品种‘周麦22’为试验材料,设置3种土壤含水量处理:田间持水量的70%~80%(W1)、60%~70%(W2)、50%~60%(W3)。在小麦小花退化高峰期前进行叶面喷施100μmol/L外源MT处理,并以清水为对照(CK),自叶面喷施MT 3天起至开花期,每3天取1次样,在EMZ-TR解剖镜下观察小麦主茎幼穗分化进程,记录分化小花数、可孕小花数及小花分化各阶段特征。然后将小麦植株分为茎(茎+叶鞘)、叶、穗三部分,调查干重、含水量、顶展叶片过氧化氢(H_(2)O_(2))和丙二醛(MDA)含量,以及抗氧化相关酶(SOD、POD)活性。【结果】与W1处理相比,W2和W3处理下两品种小麦小花总分化小花数、退化结点小花数、可孕小花数和穗粒数均降低,同时小麦植株含水量下降,顶展叶片H_(2)O_(2)和MDA含量升高。喷施外源MT可以改善两品种小麦小花发育质量,减少小花退化,增加退化结点小花数、可孕小花数,提高结实穗粒数,对品种周麦22的促进效应高于豫麦49-198。外源MT有效降低了小麦顶展叶片H2O2和MDA含量,其中豫麦49-198和周麦22的H2O2降幅分别为6.83%~15.16%、7.60%~17.06%,MDA降幅分别为5.80%~15.31%、6.94%~16.83%;有效提高了两品种顶展叶片SOD和CAT抗氧化酶活性,豫麦49-198和周麦22的SOD活性提升幅度分别为4.25%~13.39%和5.62%~14.49%,CAT活性提升幅度分别为4.86%~15.68%和5.42%~16.50%,对品种周麦22的调控效应高于豫麦49-198。喷施外源MT有效提高了两品种小麦抗氧化能力和抗旱性,进而促进干物质生产和提高穗器官干物质积累量,在喷施处理后第15天时,豫麦49-198和周麦22喷施MT处理的穗器官干物质积累量相比于喷施清水处理分别平均提高6.66%~11.72%和8.06%~12.52%,�【Objectives】Exogenous melatonin(melatonin,MT)is capable of increasing the stress resistance of crops.We studied the mechanism of MT on the drought resistance of wheat from the aspects of development of spike and floret.【Methods】A field experiment was conducted using a multi-spike cultivar‘Yumai 49-198’and a large-spike cultivar‘Zhoumai 22’as experimental materials.Three soils were watered to 70%-80%,60%-70%,and 50%-60%of field water capacities to simulate the treatments of normal(W1),mild and moderate drought stress(W2,and W3),respectively.Before the peak of floret degradation,the wheat under each water condition was foliar sprayed with 100μmol/L melatonin(MT)and clear water control(CK),respectively.The development of floret and spikelet in the main stems were observed since the 3rd day of MT treatment,with frequency of every three days until the end of flowering stage,and the plant water content,hydrogen peroxide(H2O2)and malondialdehyde(MDA)contents,and enzyme activities were determined at the same time.【Results】Compared with W1 treatment,W2 and W3 treatments reduced the total number of differentiated florets,the numbers of degenerated nodal florets and fertile florets,and the grain number per spike in both wheat cultivars,and led to a decrease in the water content of wheat plants,and an increase in the content of H2O2 and MDA in top spread leaves.MT treatment improved the quality of floret development,reduced floret degradation,increased the number of degraded nodal florets,fertile florets and grains in fruiting spikes in both cultivars,and the promotional effect on cultivar Zhoumai 22 was higher than on Yumai 49-198.MT treatment effectively reduced leaf MDA and H2O2 contents by 5.80%-15.31%and 6.83%-15.16%in Yumai 49-198,and by 6.94%-16.83%and 7.60%-17.06%in Zhoumai 22,increased the activities of SOD and CAT by 4.25%-13.39%and 4.86%-15.68%in Yumai 49-198,and by 5.62%-14.49%and 5.42%-16.50%in Zhoumai 22,respectively,and the regulatory effect on Zhoumai 22 was higher than on Yumai 49-198.MT

关 键 词：水分胁迫 褪黑素 穗花发育 抗氧化特性 干物质积累 

分 类 号：S512.1[农业科学—作物学]