太阳辐射减弱和臭氧浓度增加对大豆荧光特性与产量的影响

【目的】研究太阳辐射减弱和臭氧（O3）浓度增加单因子及复合作用条件下对大豆荧光特性与产量的影响，为应对两因素对我国农作物的不利影响提供基础理论依据。【方法】以八月黄大豆品种为试材，采用大田开顶式气室（OTC）进行太阳辐射减弱和O3浓度增加单因子及其复合条件下对大豆荧光特性与产量的影响试验。试验设4个处理，分别为：CK（不通O3、不作辐射减弱处理）、T1（不通O3，辐射减弱20％）、T2（100nL／LO3处理）、T3（100nL／LO3和辐射减弱20％复合处理）。【结果】相对于CK，T1、T2、T3处理条件下大豆的Pm、Ik、Yield、qP显著下降；L（PFD）、NPQ、Y（NPQ）、（1-qP）／NPQ显著增大；T1、T2、T3处理对快速光响应曲线的初始斜率（α）没有明显影响；T1处理对Fv/Fm值无明显影响，T2、T3处理的Fv/Fm。值显著下降；T1处理的Y（NO）值显著增大，T2处理的Y（NO）值显著减小，而T3处理没有显著改变Y（NO）值。相对于CK，T1、T2、T3处理条件下大豆的固氮能力、生物量和产量均显著降低，且呈T1〈T2〈T3的趋势。【结论】太阳辐射减弱和O3浓度增加复合条件下相对于单因子胁迫具有更明显的胁迫效应，但复合效应小于单因子胁迫效应的简单累加。太阳辐射减弱和O3浓度增加在很大程度上影响了大豆的光合作用，造成大豆减产。

Combination effects of reduced radiation and enhanced O3 stress on chlorophyll fluorescence characteristics and yield of soybean

Objective ]Effects of enhanced ozone stress and reduced solar irradiance on the chlorophyll fluorescence responses of soybean were studied to provide theoretical references for reducing the negative effects of the two elements on crops in China. Method]The field open top chamber （OTC） was applied to reduce solar irradiance and enhance ozone stress. August yellow soybean variety was used to evaluate the effects of enhanced ozone stress and reduced solar irradiance on yield and chlorophyll fluorescence responses of soybean. Four treatments were performed in field （CK, OTC; T1, 80% natural light; T2, 100 nL/L^1 O3; T3, 100 nL/L O3 and 80% natural light）. Result]Pro, Ik, yield and qP of T1, T2, T3 treatments decreased significantly compared to CK. L（PFD）,NPQ,Y （NPQ）, （1-qP）/NPQ of T1, T2, T3 treatments increased significantly compared to CK. The α of rapid light responding curve in T1, T2 and T3 treatments had no significant difference compared to CK. T1 treatment had no significant influence on FJFm. Fv/Fm of T2, T3 treatments decreased significantly compared to CK. Y（NO） of T1 treatment increased significantly compared to CK. Y（NO） of T2 treatment decreased significantly compared to CK. T3 treatment had no significant influence on Y （NO）. Soybean nitrogen-fixing ability, biomass and yield of T1, T2 and T3 treatments decreased significantly compared to CK（T1〈T2〈T3）. Conclusion]Solar irradiance and O3 combination enhanced the negative effects on chlorophyll fluorescence characteristics of soybean, while the interactive effects were less than addition of single factor. Reduced solar irradiance and enhanced O3 stress could tremendously decrease the photosynthesis and yield of soybean.