| 水分胁迫对寒地水稻光合速率、气孔限制值及WUE的影响 |
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| 作者单位： | ;1.东北农业大学水利与土木工程学院;2.农业部农业水资源高效利用重点试验室 |
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| 摘 要： | 【目的】研究不同生育阶段水分胁迫对水稻叶片光合速率的影响以及水分胁迫条件下水稻叶片光合速率变化对气孔限制值的响应规律,明确不同生育阶段水分胁迫对水稻光合特性和水分利用的综合影响,探寻水稻不同生育阶段适宜的水分管理模式。【方法】采用盆栽实验,以常规淹水灌溉模式土壤水分条件作为对照,在水稻分蘖、拔节、抽穗和乳熟期分别设置轻旱、中旱、重旱3种水平的水分胁迫,共12种处理,每个生育阶段设置正常供水作为对照,并对水稻叶片光合参数进行了测定。【结果】正常供水的水稻由于光合"午睡"现象的影响,光合速率日变化曲线为"M"型。处于低谷时间段的轻度、中度水分胁迫会减轻"午睡",使该时间段的光合速率高于CK,其余时间段随着水分胁迫程度增加,水稻叶片的光合速率逐渐降低;重度水分胁迫使光合速率在各个生育阶段处于较低水平。分蘖期、抽穗期、乳熟期进行轻度水分胁迫显著增加了气孔限制值和水分利用效率;而重度水分胁迫使抽穗、乳熟期的气孔限制值显著降低,对水分利用效率影响不显著。【结论】水稻单生育阶段轻度的水分胁迫可以有效减轻"午睡"现象,从而使"午睡"时的叶片光合速率高于正常供水,并保证了水分的高效利用。
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| 关 键 词： | 水稻 水分胁迫 不同生育阶段 光合速率 气孔限制值 水分利用效率 |
Effects of Water Stress on Photosynthetic Rate and Stomatal Restriction Value of Rice in Cold Region |
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| Institution: | ,School of Water Conservancy and Civil Engineering, Northeast Agricultural University,Key Laboratory of Agricultural Water Resource Use, Ministry of Agriculture |
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| Abstract: | 【Objective】Study the effects of water stress on photosynthetic rate of rice leaves at different growth stages and the response of photosynthetic rate to stomatal limitation under water stress, clarify the comprehensive effects of water stress at different growth stages on photosynthetic characteristics and water use of rice, and explore the suitable water management model for rice at different growth stages.【Method】Pot experiments were conducted to compare the soil water conditions of conventional flooding irrigation mode with 12 treatments of light drought, moderate drought and severe drought at the tillering, jointing, heading and milking stages. Normal water supply was used as control at each growth stage, and photosynthetic parameters of rice leaves were measured.【Result】The diurnal variation curve of photosynthetic rate of rice with normal water supply changed with "M" type due to the effect of photosynthesis "napping" phenomenon. The light and moderate water stress in the trough period could alleviate the "nap" and make the photosynthetic rate in this period higher than CK. The photosynthetic rate in rice leaves gradually decreased with the increase of water stress in other periods. Severe water stress resulted in a lower photosynthetic rate in each growth stage. Light water stress during tillering, heading and milk-ripening significantly increased stomatal limit value and WUE, and reached extremely significant level at jointing stage, while severe water stress significantly reduced stomatal limit value at heading and milk-ripening stage, and had no significant effect on WUE.【Conclusion】Mild water stress at single growth stage of rice can effectively alleviate the phenomenon of "napping", so that the photosynthetic rate of leaves during "napping" is higher than that under normal water supply, and the efficient utilization of water is ensured. |
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| Keywords: | rice water stress different growth stages photosynthetic rate stomatal limit value water use efficiency |
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