光合特性、水分利用及玉米产量受土壤水分稳定性的影响。
Photosynthetic traits, water use and the yield of maize are influenced by soil water stability.
作者信息
Li Ge, Long Huaiyu, Zhang Renlian, Xu Aiguo, Niu Li
机构信息
State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China/ Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, 12 South Road, Zhongguancun, Beijing, Haidian District, 100081, PR China.
Institute of Farmland Irrigation, Chinese Academy of Agricultural Sciences, Xinxiang, Henan, 453002, PR China.
出版信息
BMC Plant Biol. 2024 Dec 23;24(1):1235. doi: 10.1186/s12870-024-05942-4.
BACKGROUND
The aim of this study is to investigate the effect of soil water stability on maize (Zea mays L.) yield, water use, and its photosynthetic physiological mechanisms, and to innovate the relationship between maize and soil water, which currently only considers soil water content and neglects soil water stability.
METHODS
An organized water experiment was conducted on maize. The effects of stable soil water (SW) at two water content levels were examined, with fluctuating soil water (FW) as a control. The assessed effects included leaf water, chlorophyll, gas exchange, leaf water use efficiency (WUE), stable carbon isotope ratio (δC), and yield of maize.
RESULTS
Soil water stability had a significant effect on maize yield, yet it was slightly smaller than soil water content. Compared with FW, SW increased the maximum net photosynthetic rate, saturated light intensity, stomatal conductance, SPAD, leaf water content, and leaf WUE, and decreased δC, promoting dry matter assimilation and conversion into grain yield, ultimately increasing yield by 100.8%. Under the same soil water stability, 55% FC versus 75% FC weakened photosynthetic capacity and exacerbated stomatal limitation of maize leaves, making them more susceptible to light inhibition, which decreased photoassimilate accumulation, resulting in a significant decrease in yield. And the δC under 75% FC conditions decreased by 4.7-7.7% compared with 55% FC.
CONCLUSION
In conclusion, SW exhibits a positive effect on maize leaf water content, photosynthetic carbon assimilation, and grain yields, regardless of soil water content. Compared to FW, SW increased leaf WUE and maize yield by enhancing photosynthesis, and SW has stronger discrimination against C during photosynthetic CO assimilation, thus decreasing leaf δC. This study fills a gap in understanding how soil water stability influences maize yield and gas exchange, and provides a fresh perspective on how to improve crop yield and WUE by managing soil water stability.
背景
本研究旨在探究土壤水分稳定性对玉米（Zea mays L.）产量、水分利用及其光合生理机制的影响，并创新目前仅考虑土壤含水量而忽视土壤水分稳定性的玉米与土壤水分之间的关系。
方法
对玉米进行有序水分试验。研究了两个水分含量水平下稳定土壤水分（SW）的影响，并以波动土壤水分（FW）作为对照。评估的影响包括玉米叶片水分、叶绿素、气体交换、叶片水分利用效率（WUE）、稳定碳同位素比率（δC）和产量。
结果
土壤水分稳定性对玉米产量有显著影响，但略小于土壤含水量。与FW相比，SW提高了最大净光合速率、饱和光强、气孔导度、SPAD值、叶片含水量和叶片WUE，并降低了δC，促进了干物质同化并转化为籽粒产量，最终使产量提高了100.8%。在相同的土壤水分稳定性下，55%田间持水量（FC）与75% FC相比，削弱了玉米叶片的光合能力，加剧了气孔限制，使其更易受到光抑制，导致光合产物积累减少，产量显著下降。并且75% FC条件下的δC比55% FC降低了4.7 - 7.7%。
结论
总之，无论土壤含水量如何，SW对玉米叶片含水量、光合碳同化和籽粒产量均表现出积极影响。与FW相比，SW通过增强光合作用提高了叶片WUE和玉米产量，并且SW在光合CO同化过程中对C有更强的分馏作用,从而降低叶片δC。本研究填补了关于土壤水分稳定性如何影响玉米产量和气体交换方面认识的空白，并为通过管理土壤水分稳定性提高作物产量和WUE提供了新的视角。
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