Effects of high temperature stress on spring maize and its technologic solutions in North China Plain | 华北春玉米高温胁迫影响机理及其技术应对探讨

Chinese. 本研究针对华北平原春玉米一熟制高产的限制因子（灌浆期高温胁迫）问题,在分析了国内外高温对玉米胁迫影响机理的相关研究基础上,对华北平原春玉米可能突破灌浆期高温胁迫、实现高产的技术途径进行了探讨。结果表明,高温对华北春玉米胁迫的主要表现是：缩短了籽粒线性增长持续期;减小了籽粒体积及同化物向籽粒的转移量,进而降低了灌浆速率;花粉败育和花期不遇导致结实率下降;地温超过35℃时,会降低根系生长速率,使侧根变细;降低了光合酶活性、叶绿素含量及PSⅡ功能,进而降低了光合能力;降低了叶片水分状态和植株氮素累积量;诱发了纹枯病和青枯病。要突破该区春玉米灌浆期的高温胁迫,需要从提高春玉米本身的机能和改善其生境调控着手,躲避高温（提前或推迟播期）和抗耐高温（选育耐热性品种;外施水杨酸（SA）、激动素（BA）、脱落酸（ABA）等化学调控;在灌浆期之前进行高温锻炼;有机肥、铜肥、锌肥、钾肥等营养调控;深松和垄作等耕作调控;优化灌溉制度等水分调控;调整株距和行距改善种植方式等方面）。在单项技术研究的基础上,系统设计、集成各项单项技术,形成综合技术体系,是该区春玉米高产的技术途径。

English. This paper studied limiting factor （high temperature stress occurred during grain filling period） for high yield production of spring maize in North China Plain（NCP）.By analyzing the available high yield technologic solutions for spring maize under high temperature stress （HTS）,we expected that spring maize might break the barriers from HTS during grain filling period in NCP.The results showed that the main clinical manifestations of spring maize under HTS at filling stage included,shortened the linear growth stage of maize grain;reduced the grain size and the amount of assimilate transfer to grain,leading to a reduced grain filling rate;pollen abortion and mismatched pollination period which reduced seed setting rate;the temperature over 35℃ would reduce root growth rate and hindered the lateral root growth;reduced photosynthetic enzyme activity,chlorophyll content and PSII function,which resulting in photosynthesis reduction;lowered leaf water status and plant nitrogen accumulation;induced sheath blight and bacterial wilt.To break the barrier exerted by HTS on spring maize during grain filling stage,the following practices could be used：advancing or delaying sowing date to avoid high temperature,breeding high temperature tolerant maize varieties;applying chemicals such as exogenous salicylic acid （SA）,kinetin （BA） and abscisic acid （ABA） to improve the tolerance;pre-exercising with high temperature well before the grain filling stage;practicing agronomic and farming approaches to regulate the nutrition levels and soil and water and light properties.Based on this study,a design integrated technology of the individual techniques could be used to form an integrated technology system,thus to improve heat tolerance and increase spring maize yield under HTS in NCP.