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通过对防雨棚下测坑中种植的夏玉米设置不同的土壤水分控制下限,研究了不同的土壤水分状况及气象因子对夏玉米叶片生理特性的影响。结果表明,各生理指标受生态因子的影响有着明显的日变化特征,不同处理气孔导度(Gs)峰值出现的时间早于光合速率(Pn)和蒸腾速率(Tr),高水分下Tr峰值出现的时间滞后于Pn,随着土壤水分胁迫程度的增加,Gs、Tr、Pn的峰值有提前出现的趋势;不同土壤水分条件下细胞液浓度(CSC)的峰值及叶水势(LWP)的低谷均在14:00左右出现。土壤水分与Tr、Pn、Gs、LWP呈极显著正相关,而与CSC呈极显著负相关。此外,气象因素对夏玉米生理指标的影响程度会随着土壤水分状况而发生变化,生理指标与生态因子的逐步回归结果表明,土壤水分和光合有效辐射是影响夏玉米生理指标最主要的生态因子。
By setting different lower limit of soil moisture control for summer maize planted under shelter, the effects of different soil moisture conditions and meteorological factors on the physiological characteristics of summer maize were studied. The results showed that each physiological index had obvious diurnal variation under the influence of ecological factors. The peak of stomatal conductance (Gs) occurred earlier than photosynthetic rate (Pn) and transpiration rate (Tr), Tr peak under high water stress The peak of Gs, Tr and Pn appeared ahead of time. The peak value of CSC and the lowest of LWP under different soil moisture conditions Appeared around 14:00. Soil moisture had a significant positive correlation with Tr, Pn, Gs and LWP, but a significantly negative correlation with CSC. In addition, the degree of influence of meteorological factors on summer maize physiological indices will change with the soil moisture status. The stepwise regression of physiological indicators and ecological factors indicates that soil moisture and photosynthetic active radiation are the most important ecological factors affecting summer maize physiological indices .