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为阐明枫杨对三峡库区消落区土壤不同含水量的适应机理,模拟三峡库区消落区土壤水分变化特征,设置了常规土壤水分(T1)、土壤水分饱和(T2)及根部水淹(T3)3个不同条件处理组,研究了枫杨当年实生幼苗的光合色素含量、光合生理和叶绿素荧光特性.研究结果发现:经过1 a水淹后,土壤不同含水量对枫杨幼苗光合色素、气体交换参数、资源利用效率和叶绿素荧光参数有不同的影响,其中T2、T3的气孔导度(Gs)、蒸腾速率(Tr)、胞间CO2浓度(Ci)和水分利用效率(WUE)与对照组T1相比没有显著变化;而其净光合速率(Pn)、光能利用效率(LUE)、CO2利用效率(CUE)显著下降(p<0.05),但T3组枫杨幼苗仍然具有较高的Pn,LUE,CUE;随着水淹强度的增大,枫杨幼苗的PSⅡ最大光化学效率(Fv/Fm)、PSⅡ光化学的量子效率(ΦPSⅡ)和光化学淬灭(qP)逐渐降低,非光化学淬灭(NPQ)逐渐升高.研究证实枫杨幼苗在经过长达1 a水淹后,仍然表现出较高的光合能力,是一种可以用于三峡库区消落区植被构建的优良植物物种.
In order to clarify the adaptation mechanism of Pinus tabulaeformis to different soil water content in the fluctuation area of the Three Gorges Reservoir and to simulate the variation characteristics of soil moisture in the fluctuation area of the Three Gorges Reservoir, conventional soil moisture (T1), soil water saturation (T2) and root flooding (T3) were used to study the photosynthetic pigment content, photosynthetic physiology and chlorophyll fluorescence characteristics of seedlings of Pterocarya stenoptera L. The results showed that after 1-a-year flooding, the photosynthetic pigments (Gs), transpiration rate (Tr), intercellular CO2 concentration (Ci) and water use efficiency (WUE) of T2 and T3 were significantly correlated with chlorophyll fluorescence parameters, gas exchange parameters, resource use efficiency and chlorophyll fluorescence parameters The photosynthetic rate (Pn), light use efficiency (LUE) and CO2efficiency (CUE) of the control group were significantly decreased (p <0.05), but the T3 group was still higher Pn, LUE and CUE. The maximum PSⅡ photochemical efficiency (Fv / Fm), PSⅡ photochemical quantum efficiency (ΦPSⅡ) and photochemical quenching (qP) decreased with the increase of flooding intensity. Quenching (NPQ) gradually increased. Studies have confirmed that Poplar seedlings in the past After up to 1 year of flooding, it still showed higher photosynthetic capacity and was a good plant species that could be used for vegetation construction in the watershed of the Three Gorges Reservoir area.