干旱气象 ›› 2025, Vol. 43 ›› Issue (2): 176-185.

• 论文 • 上一篇    

干旱胁迫下春玉米七叶期光合特性及其响应机理

唐玉瑞1,2,3,4 ,齐 月1,2,3,4 ,王鹤龄1,2,3,4 ,杨 阳1,2,3,4 ,赵 鸿1,2,3,4 ,张 凯1,2,3,4 ,魏星星1,2,3,4 ,王仁奎5
  

  1. 1. 中国气象局兰州干旱气象研究所,甘肃省干旱气候变化与减灾重点实验室,中国气象局干旱气候变化与减灾重点实验室,
    甘肃 兰州 730020;2. 中国气象局定西干旱气象与生态环境野外科学试验基地,甘肃 定西 743000;
    3. 中国气象局武威国家气候观象台,甘肃 武威 733000;4. 中国气象局张掖国家气候观象台,
    甘肃 张掖 734000;5. 甘肃省靖远县气象局,甘肃 靖远 730600
  • 出版日期:2025-04-30 发布日期:2025-05-13
  • 作者简介:唐玉瑞(1997—),女,甘肃靖远人,研究实习员,主要从事作物干旱致灾机理研究。E-mail:2959869008@qq. com。

Photosynthetic characteristics and response mechanism of spring maize at seven-leaf stage under drought stress

TANG Yurui1,2,3,4, QI Yue1,2,3,4, WANG Heling1,2,3,4, YANG Yang1,2,3,4, ZHAO Hong1,2,3,4,
ZHANG Kai1,2,3,4, WEI Xingxing1,2,3,4, WANG Renkui5
  

  1. 1. Institute of Arid Meteorology, China Meteorological Administration, Key Laboratory of Arid Climatic Change and Reducing Disaster of Gansu Province, Key Laboratory of Arid Climatic Change and Disaster Reduction of CMA, Lanzhou 730020, China;
    2. Dingxi Drought Meteorology and Ecological Environment Field Scientific Experimental Station of CMA,Dingxi 743000, Gansu, China;3.  Wuwei National Climate Observatory of China Meteorological Administration, Wuwei 733000, Gansu , China ;4. Zhangye National Climate Observatory of China Meteorological Administration . Zhangye  734000, Gansu , China 
    5. Jingyuan Meteorological Bureau of Gansu Province, Jingyuan 730600, Gansu, China
  • Online:2025-04-30 Published:2025-05-13

摘要:

干旱胁迫是限制作物生长的主要因素,研究春玉米(Zea mays L.)苗期光合特性与生理抗旱机制,对有效抗御干旱、促进作物产量形成等方面具有重要意义。以春玉米为研究对象,采用盆栽试验,设置对照处理(简称“CK”处理)、轻度干旱(T1)、中度干旱(T2)、重度干旱(T3)4种梯度,研究不同干旱程度下春玉米七叶期叶片的光合生理特征及其抗旱机制。结果表明:干旱显著降低了春玉米叶片的净光合速率(Pn )及最大净光合速率(Pnmax);光响应曲线的初始斜率(α0 )、暗呼吸速率(Rd )、表观量子效率(Apparent Quantum Efficiency,AQE)在中度、重度干旱处理下显著下降,光饱和系数(γ0 )显著增加,叶片的光能利用率显著下降;蒸腾速率(Tr )随着干旱胁迫的加剧逐渐降低,水分利用效率(Water Use Efficiency,WUE)在中度干旱处理下显著增加,重度干旱下显著降低;气孔导度(Gs )随着干旱胁迫的加剧逐渐下降,轻度、中度干旱处理下净光合速率下降的因素以气孔限制为主,轻度干旱下存在气孔非均匀关闭现象,重度干旱下胞间CO2浓度(Ci )显著上升,气孔限制值(Ls )显著降低,以非气孔限制为主导因素。

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Abstract:

Drought stress is a major limiting factor for crop growth. Investigating the photosynthetic characteristics and physiological
drought resistance mechanisms of spring maize (Zea mays L.) at the seedling stage is crucial for enhancing drought resilience and promoting crop yield. In this study, taking spring maize as the research object and using pot experiments, four gradients of control treatment (referred to as “CK” treatment), mild drought (T1), moderate drought (T2), and severe drought (T3) were set up to study the photosynthetic physiological characteristics and drought resistance mechanism at the seven-leaf stage of spring maize under different drought degrees. The results show that drought stress significantly reduced both the net photosynthetic rate (Pn) and the maximum net photosynthetic rate (Pnmax) of spring maize leaves. Under moderate and severe drought conditions, the initial slope (α0), the dark respiration rate (Rd), and the apparent quantum efficiency (AQE) of the light response curve decreased significantly, while the light saturation coefficient (γ0) increased markedly, indicating the light energy utilization rate of the leaves decreased significantly. The transpiration rate (Tr ) gradually decreased with increasing of drought intensity, the water use efficiency (WUE) significantly enhanced under moderate drought but sharply reduced under severe drought. Stomatal conductance (Gs ) progressively declined with drought stress intensification. Stomatal limitation was identified as the primary factor reducing photosynthetic rate under mild and moderate drought conditions, with non-uniform stomatal closure phenomenon under mild drought. Under severe drought condition, intercellular CO2 concentration (Ci ) significantly increased, and the stomatal limitation value (Ls ) decreased dramatically, demonstrating the dominance of non-stomatal limitation.

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