| 摘要: |
| 【目的】研究水分胁迫下冬小麦叶片气孔行为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和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】本试验中，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总是最低；两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的降幅总是最大；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以下水平，其与气孔导度（Gs）、蒸腾速率（Tr）间存在着显著的线性相关关系；基于叶片水分利用效率（WUEl）与净光合速率（Pn）、Tr、Gs间的曲线关系，分别确定了周麦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。【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；通过气体交换参数可对作物自身所处的土壤水分状况进行准确判断，并量化了判定标准。 |
| 关键词: 冬小麦；水分胁迫；水分利用效率；气孔限制；周麦22 |
| DOI： |
| 分类号:S274.1 |
| 基金项目: |
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| Response of Gas Exchange Parameters of Winter Wheat to Water Stress |
|
qiuxinqiang
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|
henan provincial water conservancy research institute
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| Abstract: |
| 【Objective】The objective is to define the response mechanism of leaf stomatal behavior under water stress and its relationship with yield.【Method】Through lysimeter experiments, the variation of leaf gas exchange parameters, grain yield, water consumption of winter wheat under different growth stages and water deficits were compared and analyzed.【Result】In this experiment, the total water consumption of winter wheat was reduced by drought at any growth period, and the total water consumption of severe drought treatments were always the lowest; In the two seasons, the average yield reduction and water consumption reduction of winter wheat were about 9.89% and 2.89% (light drought), 14.72% and 7.46% (medium drought), 23.62% and 21.85% (severe drought), respectively; Drought in the seedling stage had a limited effect on the gas exchange process of winter wheat leaves, and it would be more affected after jointing; The compensation growth occurred after rewatering at jointing stage, and long-term continuous drought would significantly inhibit the leaf gas exchange process of winter wheat; The stomatal limit value of winter wheat has a significant linear correlation with Gs and Tr, and its value was concentrated below 0.3; Based on the curve relationship between WUE1 and Pn, Tr and Gs, the theoretical calculated values of WUE1 under light, moderate and severe water stress were determined respectively.【Conclusion】It is beneficial to promote root growth by maintaining suitable soil water stress in the seedling stage. After jointing, severe water stress and long- term continuous drought can significantly inhibit the gas exchange process of winter wheat leaves. In production, such phenomena should be avoided as much as possible. The gas exchange parameters can be used to accurately judge water stress, and the judgement standard were given. |
| Key words: winter wheat; water stress; water use efficiency; stomatal limit; zhoumai22 |
