Evaluation of the physiological significance of leaf wetting by dew as a supplemental water resource in semi-arid crop production
Evaluation of the physiological significance of leaf wetting by dew as a supplemental water resource in semi-arid crop production
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DOI：
10.1016/j.agwat.2021.106964
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发表时间：
2021-09
影响因子：
6.7
通讯作者：
G. Yokoyama;D. Yasutake;Keisuke Minami;Kensuke Kimura;Atsushi Marui;Wu Yueru;Jiaojiao Feng;
中科院分区：
文献类型：
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作者：
G. Yokoyama;D. Yasutake;Keisuke Minami;Kensuke Kimura;Atsushi Marui;Wu Yueru;Jiaojiao Feng;
露水是一种经常观测到的气象现象，其对干旱和半干旱地区水平衡的重要性已得到公认。我们的研究重点是评估潜在的意义，叶面湿润露水半干旱作物生产的植物生理功能的影响。我们在西北地区的玉米地进行了田间试验。露水湿润叶片发生在45%的天在培养期间，叶水势较高的露水湿润的叶片比那些没有润湿在上午。此外，我们进行了一个盆栽玉米控制实验，包括四个处理（两个不同的土壤水分处理：水胁迫和充分浇水，和两个不同的叶片湿润处理：有和没有叶片湿润）。水分胁迫处理强烈抑制植物生理功能（叶水势降低，气孔关闭，光合速率降低），因此，生长速率下降。而在水分胁迫下的湿润区，玉米叶片在夜间从表面吸收水分，显著提高了黎明前的叶水势。因此，该小区表现出较高的光合速率比水分胁迫无叶湿润小区在白天。在水分充足的小区中，叶片湿润对植物生理功能的正效应不明显。我们认为，叶片湿润的积极影响主要表现为对植物水分关系的影响，这种影响可能是有限的，当植物有足够的水分。结果表明，叶片湿润的水分胁迫植物表现出更高的水分利用效率。我们的研究结果表明，露水湿润叶作为一种水资源在半干旱作物生产中的重要性，因为它对植物生理功能的影响。
Dew is a frequently observed meteorological phenomenon and its importance to the water balance in arid and semi-arid regions has been recognized. The focus of our study was to evaluate the potential significance of leaf wetting by dew on semi-arid crop production in terms of its effects on plant physiological functions. We conducted a field experiment in a maizefield in northwest China. Leaf wetting by dew occurred on 45% of days during cultivation periods, and leaf water potential was higher for leaves wetted by dew than for those not wetted during the morning. In addition, we conducted a potted maize control experiment consisting of four treatments (two different soil water treatments: water-stressed and well-watered, and two different leaf wetting treatments: with and without leaf wetting). The water-stressed treatment strongly inhibited plant physiological functions (decrease in leaf water potential, stomatal closure, decrease in photosynthetic rate); therefore, growth rate decreased. However, in the water-stressed with leaf wetting plot, the maize leaves absorbed water from their surfaces during nighttime, which significantly increased pre-dawn leaf water potential. Consequently, this plot showed a higher photosynthetic rate than did the water-stressed without leaf wetting plot during daytime. The positive effects of leaf wetting on plant physiological functions were not explicit in the well-watered plots. We assumed that the positive effects of leaf wetting were mainly manifest as effects on plant–water relations; such effects may be limited when plants have sufficient water. As a result, water-stressed plants with leaf wetting showed greater water use efficiency. Our results indicate the importance of leaf wetting by dew as a water resource in semi-arid crop production owing its effects on plant physiological functions.