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基于七叶期开始的夏玉米全生育期不同强度的干旱发生发展模拟试验资料,分析了不同强度的干旱发生发展对夏玉米叶片含水率及光合特性的影响。结果表明:夏玉米生育期内叶片含水率随干旱发生发展呈线性下降趋势,并与土壤相对湿度通过0.005水平的显著性检验,可表征玉米的受旱程度。玉米全生育期内叶片的光合速率、蒸腾速率和气孔导度均随干旱的发生发展呈显著下降趋势,且不同强度干旱的影响差异随时间推移而减小;而叶片水分利用效率则随干旱发生发展呈升高趋势,且随着干旱的发展不同强度干旱间的差异呈增加趋势。玉米全生育期内均出现了光合作用由气孔限制向非气孔限制的转换,转换时间分别为46、38、30和35 d,与干旱强度及持续时间呈反比。
Based on the simulation test data of different intensities of drought during the whole growth period of summer maize, the effects of different intensities of drought on the leaf water cut and photosynthetic characteristics of summer maize were analyzed. The results showed that the leaf moisture content of summer maize decreased linearly with the development of drought, and the soil moisture could pass 0.005 significance test to characterize the drought degree of maize. The photosynthetic rate, transpiration rate and stomatal conductance decreased with the development of drought during the whole growth period of maize, and the difference of drought intensity with different intensity decreased with time; however, the water use efficiency of leaves varied with the occurrence of drought The trend of development showed an increasing trend, and the differences between different intensities of drought showed an increasing trend with the development of drought. During the whole growth period of maize, photosynthesis changed from stomatal limitation to non-stomatal limitation, and the conversion time was 46, 38, 30 and 35 d, respectively, which was inversely proportional to drought intensity and duration.