| 摘要: |
| 【目的】探讨玉米开花期遭遇高温胁迫后合理施用氮肥对其生理特性、干物质积累及产量的影响。【方法】以耐热型玉米品种郑单958(ZD958)和热敏感型玉米品种先玉335(XY335)为材料，采用盆栽种植方式，共设4个施氮水平(0，75，150和225 kg/hm2，分别标记为N0、N1、N2和N3)为主区，以2个温度梯度为副区，即温室内高温处理(（35±2） ℃，HT)和室外自然温度(（30±2） ℃，CK)。于玉米开花期进行持续5 d高温处理，测定花后不同时期、不同玉米品种的生理特性(叶面积指数(LAI)，相对叶绿素含量(SPAD)，叶片持绿性，超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性，丙二醛(MDA)和脯氨酸(Pro)含量及花粉活力)、干物质积累及产量指标。【结果】高温胁迫抑制了玉米叶片的LAI、SPAD和持绿性的提升，扰乱了抗氧化酶的正常合成，增加了脂膜过氧化产物及渗透调节物质的积累，但降低了玉米的花粉活力。合理的氮肥用量可通过提高玉米叶片的LAI、SPAD和持绿性，增加SOD、POD、CAT活性和Pro含量，降低MDA含量，有效缓解高温胁迫对玉米叶片正常代谢的不利影响，增加了光合产物积累，改善了干物质积累特性。在玉米产量及其构成因素方面，花期高温胁迫后显著降低了玉米的百粒质量和籽粒产量。与N0相比，高温胁迫后N2处理ZD958和XY335的籽粒产量分别提高40.79%和51.20%，ZD958的籽粒产量较XY335提高15.61%，说明合理施氮可有效缓解高温胁迫对玉米籽粒产量的不利影响，以N2处理表现最优。主成分分析结果表明，高温胁迫后各氮素处理的ZD958和XY335综合得分均呈现N2＞N3＞N1＞N0。【结论】玉米花期高温胁迫下，施氮量保持在150 kg/hm2可持续优化玉米叶片生理特性和干物质积累特性，进而提高产量，以实现合理施氮对玉米花期高温胁迫的补偿。 |
| 关键词: 玉米 高温胁迫 氮肥用量 叶片生理特性 干物质积累特性 玉米栽培 |
| DOI：10.13207/j.jnwafu.2026.02.005 |
| 分类号: |
| 基金项目:宁夏高质量发展与生态保护科技创新示范项目(NGSB-2021-3-02);宁夏回族自治区自然科学基金项目(2021AA-C03072);宁夏回族自治区重点研发项目(2019BBF02003);宁夏粮食作物种质创制与生长调控科技创新团队项目(2022BSB03109) |
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| Effect of nitrogen fertilizer application on the growth and yield of maize under high temperature stress during flowering period |
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SU Ming, WANG Hua, HONG Ziqiang, LI Fanguo, ZHOU Tian, WAN Menghu, LI Yueqi, WU Hongliang, ZHANG Shibo, KANG Jianhong
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College of Agriculture,Ningxia University,Yinchuan,Ningxia 750021,China
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| Abstract: |
| 【Objective】This research aims to explore the effects of reasonable application of nitrogen fertilizer on physiological characteristics,dry matter accumulation and yield of maize under high temperature stress during flowering.【Method】 The heat tolerant maize variety Zhengdan 958 (ZD958) and the heat-sensitive maize variety Xianyu 335 (XY335) were used as materials,and were grown in pots.A total of four N application levels (0,75,150,and 225 kg/hm2 labeled N0,N1,N2,and N3,respectively) were set as the main zones,and two temperature gradients as the sub-zones:high temperature treatment in the greenhouse ((35±2) ℃,HT) and outdoor natural temperature ((30±2) ℃,CK).The physiological characteristics (LAI,SPAD,leaf greening,SOD,POD,CAT,MDA,Pro,and pollen viability),dry matter accumulation,and yield indexes of different maize varieties were determined at different periods after the flowering of maize under continuous high temperature treatments for 5 days.【Result】High temperature stress inhibited the elevation of LAI,SPAD,and greening of maize leaves,disturbed the normal synthesis of antioxidant enzymes,increased the accumulation of lipid-membrane peroxidation products and osmotic-regulating substances,and reduced pollen viability in maize.Reasonable nitrogen fertilizer dosage could effectively alleviate the adverse effects of high temperature stress on normal leaf metabolism,increase photosynthetic product accumulation and improve dry matter accumulation characteristics by improving maize leaf LAI,SPAD and green holding,increasing of SOD,POD,CAT activity and the content of Pro,and decreasing the content of MDA.For maize yield and its components,100-kernel mass and seed yield were significantly reduced after high temperature stress at anthesis.Compared with N0,the seed yield of ZD958 and XY335 treated with N2 after high temperature stress increased by 40.79% and 51.20%,respectively,and the seed yield of ZD958 increased by 15.61% compared with that of XY335,which indicated that reasonable nitrogen application could effectively alleviate the adverse effects of high temperature stress on maize seed yield,with N2 treatment showing the best performance.Principal component analysis showed that the composite scores of ZD958 and XY335 under each nitrogen treatment after high temperature stress were ranked as N2>N3>N1>N0.【Conclusion】Under the high temperature stress at the flowering stage of maize,keeping the N application rate at 150 kg/hm2 can continuously optimize the physiological characteristics of maize leaves and dry matter accumulation characteristics,and then improve the yield,to realize the compensation of reasonable N application to the high temperature stress at the flowering stage of maize. |
| Key words: maize high temperature stress nitrogen fertilizer dosage leaf physiological characteristics dry matter accumulation characteristics maize cultivation |
