玉米叶片“源”的高温胁迫阈值研究  

Study on High Temperature Stress Threshold of Maize Leaves

作　　者：张学鹏[1] 李腾 王彪 刘晴 刘涵瑜 陶志强[2] 隋鹏[1] Zhang Xuepeng;Li Teng;Wang Biao;Liu Qing;Liu Hanyu;Tao Zhiqiang;Sui Peng(College of Agronomy and Biotechnology,China Agricultural University,Beijing 100193,China;Institute of Crop Sciences,Chinese Academy of Agricultural Sciences/Key Laboratory of Crop Physiology and Ecology,Ministry of Agriculture and Rural Affairs,Beijing 100081,China)

机构地区：[1]中国农业大学农学院,北京100193 [2]中国农业科学院作物科学研究所/农业农村部作物生理生态重点实验室,北京100081

出　　处：《作物杂志》2021年第2期62-70,共9页Crops

基　　金：国家自然科学基金(31701387,32071978)。

摘　　要：为了明确玉米叶片"源"的高温胁迫温度阈值,采用盆栽试验,利用可精准控温(模拟大气温度变化)的人工气候室,以日最高温32℃为对照,分别设置日最高温34℃、36℃和38℃3个处理,于玉米拔节期进行持续10d的温度控制试验,比较叶片光合作用光反应和暗反应阶段对不同高温的响应,以及叶片气孔和叶绿体超微结构的变化。光反应阶段,38℃处理下的光系统Ⅱ最大光化学量子产量(Fv/Fm)和实际光化学量子产量Y(Ⅱ)与其他处理相比均显著降低,但胁迫解除后均恢复至正常水平,而其他3个处理无显著性差异;暗反应阶段,与对照相比,36℃和38℃处理的叶片净光合速率(Pn)均显著降低,胞间CO2浓度(Ci)均显著升高,且38℃处理在胁迫解除后Pn未能恢复。透射电镜结果显示,在36℃和38℃处理下,叶绿体结构逐渐紊乱降解,脂质球体含量增加,淀粉粒合成减少。综上可知,对于玉米叶片"源",日最高温的胁迫阈值是36℃,阈值附近的高温胁迫主要是限制光合作用的暗反应阶段。The present research aimed to find out the high temperature stress threshold of maize leaves. Using an artificial climate chamber with accurate temperature control, a pot experiment was designed. The daily maximum temperature of 32℃ was used as the control, and three different daily maximum temperature treatments(34℃, 36℃, and 38℃) were set. The high temperature stress treatments were lasting ten days at the jointing stage. The response of photosynthetic photoreaction and dark reaction phases of leaves at different temperatures, and the ultrastructure of stomata and chloroplasts of leaves were analyzed. At the photoreaction phase, the maximum light efficiency of photosystem Ⅱ and the actual photochemical efficiency treatment were significantly reduced under the treatment of 38℃, and both indicators returned to normal levels after releasing of the high temperature stress. But the other three treatments showed no significant difference. At the dark reaction phase, the net photosynthetic rates at 36℃ and 38℃ were significantly lower than that of the control, and the intercellular CO2 concentration increased significantly, and the net photosynthetic rate at 38℃ could not return to normal level after releasing of high temperature stress. The results of the transmission electron microscope showed that under the treatment of 36℃ and 38℃, the chloroplast structure gradually disordered and degraded, the content of the lipid sphere increased, and the synthesis of starch decreased. Therefore, for the leaf of maize, the threshold of high daily maximum temperature stress was 36℃. In addition, high temperature stress near the threshold mainly restricts the dark reaction stage of photosynthesis.

关 键 词：玉米 高温胁迫 阈值 叶片 光合作用 叶绿体 

分 类 号：S513[农业科学—作物学]