| 引用本文: | 张玉顺,路振广,张明智,等.冬小麦叶片气体交换参数对水分胁迫的响应[J].灌溉排水学报,2020,39(12):32-40. |
| ,et al.冬小麦叶片气体交换参数对水分胁迫的响应[J].灌溉排水学报,2020,39(12):32-40. |
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| 摘要: |
| 【目的】研究冬小麦叶片气孔行为对水分胁迫的响应机制及其与产量的关系。【方法】以周麦22为试验材料，通过测坑控制试验，对比分析了不同生育阶段不同水分胁迫水平下冬小麦主要叶片气体交换参数，以及籽粒产量、耗水量和水分利用效率的差异。【结果】任一生育时期受旱均限制了冬小麦全生育期总耗水量的增加，重旱处理的总耗水量均最低；2季冬小麦的平均减产率和耗水量降幅分别约为9.89%和2.89%（轻旱）、14.72%和7.46%（中旱）、23.62%和21.85%（重旱）；苗期干旱对冬小麦叶片气体交换过程的影响有限，拔节以后所受影响较大，重旱处理Pn、Tr和Gs的降幅均最大；拔节期轻度水分胁迫-复水后出现补偿效应，提高了水分利用效率，长期持续受旱则会明显抑制冬小麦叶片的气体交换进程；冬小麦叶片的气孔限制值集中在0.3以下，其与气孔导度（Gs）、蒸腾速率（Tr）间存在着显著的线性关系；基于叶片水分利用效率（WUE）与净光合速率（Pn）、Tr、Gs间的曲线关系，确定了周麦22开始遭受轻度、中度和重度水分胁迫时叶片水分利用效率的理论计算值分别为2.62、3.36和4.11 μmol/mmol。【结论】苗期适当增加水分胁迫的程度有助于“蹲苗”，拔节以后重度水分胁迫和长期持续受旱明显抑制冬小麦叶片的气体交换过程，在生产中应尽量避免出现此类现象。 |
| 关键词: 冬小麦；水分胁迫；水分利用效率；气孔限制；周麦22 |
| DOI：10.13522/j.cnki.ggps.2020311 |
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| The Response of Gas Exchange Parameters of Winter Wheat Leaves to Water Stress |
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ZHANG Yushun, LU Zhenguang, ZHANG Mingzhi, DING Pengfei,WANG Hongming, YANG Haochen, QIU Xinqiang
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1. Henan Provincial Water Conservancy Research Institute/Center of Efficient Irrigation Engineering and Technology Research of Henan Province, Zhengzhou 450003, China; 2. Xuchang Experiment and Extension Station of Farmland Water Conservancy, Xuchang 461000, China
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| Abstract: |
| 【Background】Henan province is a key agricultural base in Huang-Huai-Hai plain of China, but its production is constrained by water shortage. Winter wheat is the main crop grown in this region and during its growth season the precipitation can only meet 25%~40% of its demand. As such, two-three irrigations are needed to ensure its yield. Identifying water status of the winter wheat is hence crucial to maximizing water use efficiency of the wheat in designing irrigation schedule.【Objective】The objective of this paper focuses on physiology of the wheat, investigating experimentally how gas exchange parameters of the wheat leaves respond to water stress and its consequence for yield.【Method】The experiment was conducted in lysimeters. We took the variety of Zhoumai22 as the model plant and measured in the experiment the variation in leaf gas exchange parameters, grain yield, water consumption of the wheat under water stress occurring at different growth stages.【Result】Drought occurring at any growth stage of the wheat led to a reduction in its total water consumption, especially when the drought was severe. Average reduction in the yield and water consumption over the two experimental seasons were 9.89% and 2.89% (light drought), 14.72% and 7.46% (moderate drought), 23.62% and 21.85% (severe drought), respectively. The impact of drought occurring at the seedling stage had limited effects on leaf gas exchange in the early stage but became noticeable after the jointing stage. Severe drought significantly reduced Pn, Tr and Gs, while rewetting after the jointing stage following a light drought could compensate the loss. The stomatal limit value was linearly correlated with Gs and Tr, and its value was less than 0.3. The values of WUE under different water stresses were calculated from its dependence on Pn, Tr.【Conclusion】Keeping the roots at seedling stage under a certain degree of water stress is beneficial to promoting their growth. After the jointing stage, severe water stress or long- term continuous drought could significantly impede gas exchange in the leaves and thus should be avoided. Our results showed that the leaf gas exchange parameters can be used to diagnose water stress and help design irrigation. |
| Key words: winter wheat; water stress; water use efficiency; stomatal limit; Variety of Zhoumai 22 |
