臭氧浓度升高条件下秸秆还田对大豆光合荧光特性及产量的影响

Effects of Straw Returning on Photosynthetic Fluorescence Characteristics and Yield of Soybean Under Elevated Ozone Concentration

为了探究臭氧浓度升高条件下秸秆还田对大豆叶片光合荧光特性及产量的影响,以铁丰29为试验材料,研究秸秆还田和臭氧浓度升高条件下大豆光合荧光特性及产量的变化规律。结果表明:随着O3浓度升高,大豆净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、水分利用效率(WUE)下降,胞间CO2浓度(Ci)呈先降后升的趋势;在结荚期T1处理下,S0与S1相比,Pn显著降低48.59%(P<0.05);在分枝期T2处理下,S1与S0相比,Tr、Gs显著上升51.26%和50.41%(P<0.05);PS II原初光化学效率(Fv/Fm)、PSⅡ的潜在活性(Fv/Fo)和PSⅡ的实际光化学效率(ФPSⅡ)呈先升后降的趋势,光合电子传递速率(ETR)、光化学淬灭系数(qP)降低而非光化学淬灭系数(NPQ)升高。Fv/Fo在结荚期T1处理下S1与S0相比显著降低30.13%(P<0.05)。产量与ETR、Pn呈显著正相关(P<0.05),试验表明:高浓度O3通过抑制大豆植株的光合作用、降低电子传递速率使大豆产量降低,秸秆还田在一定程度上可缓解但不能从根本上消除臭氧胁迫所带来的负面效应。

In order to investigate the effects of straw returning on photosynthetic fluorescence characteristics and yield of soybean under elevated ozone concentration,Tiefeng 29 was used as test material to study the changes of photosynthetic fluorescence parameters and yield of soybean under the conditions of straw returning and ozone concentration.The results showed that with the increase of O3 concentration,the net photosynthetic rate(Pn),transpiration rate(Tr),stomatal conductance(Gs)and water use efficiency(WUE)of soybean decreased,and the intercellular CO2 concentration(Ci)decreased firstly and then increased.The trend of Pn was significantly decreased by 48.59%(P<0.05)compared with S1 in T1 treatment.The Tr and Gs increased significantly by 51.26%and 50.41%compared with S0 in the T2 treatment(P<0.05);The initial photochemical efficiency(Fv/Fm)of PS II,the potential activity of PSⅡ(Fv/Fo)and the actual photochemical efficiency of PSⅡ(ФPSⅡ)increased firstly and then decreased,photosynthetic electron transport rate(ETR),photochemical quenching coefficient(qP)decreased rather than elevated photochemical quenching factor(NPQ).Compared with S0,F1/F0 significantly decreased by 30.13%(P<0.05).There was a significantly positive correlation between yield and ETR and Pn(P<0.05).The experiment showed that high concentration of O3 reduced soybean yield by inhibiting the photosynthesis of soybean plants and decreased the electron transfer rate.Straw returning to the field did alleviate to a certain extent but could not fundamentally eliminate the negative effects of ozone stress.