高浓度O3及太阳辐射减弱对冬小麦PSⅡ光合活性及光能耗散的影响

孙健 Sun Jian,吴荣军 Wu Rongjun,徐静馨 Xu Jingxin,李健 Li Jian,郑有飞 Zheng Youfei

doi:10.5846/stxb201111061682

Abstract

为给地表太阳辐射减弱和O3浓度增加等大气环境变化条件下我国粮食生产和安全提供安全评估依据，利用开顶式气室（OTC）和黑色遮光网开展了1种熏气水平和2种辐射减弱程度的大田试验（野外CK，T1：遮光20%，T2：遮光40%，T3：O3浓度100 nL/L，T4：O3浓度100 nL/L与遮光20%复合，T5：O3浓度100 nL/L与遮光40%复合）。结果表明：T1、T2和T4组的Fv/Fm、L（PFD）与CK均相似且变化不明显，Yield、qP、Y（NO）、（1-qP）/NPQ分别较CK不同程度下降，而NPQ和Y（NPQ）较CK分别较大程度升高；T3-T5组的Fv/Fm，L（PFD） 、Yield、qP、Y（NO）和（1-qP）/NPQ较CK不同程度降低，而NPQ和Y（NPQ）较CK分别显著升高且T5增幅显著大于T1-T4组。综上表明，复合胁迫下，冬小麦光能更多地向调节性热耗散途径分配，辐射减弱效应能使臭氧胁迫下冬小麦较好地自我调节以更好地适应逆境环境。尽管冬小麦对复合胁迫具有一定的适应能力，地表臭氧浓度升高和辐射减弱仍然是我国粮食生产中面临的一个重要问题。;At present, the aerosol radiative effect is the focus of many scholars and the solar radiation attenuated by direct or indirect effect to cause crop photosynthetic capacity decreased, resulting in crop production; At the same time the surface concentration of O3 continuously increased, O3 has strong negative effect on crop growth and metabolic processes and O3 was direct threat to food safety to crops. Providing the basis for the security of National grain assessments and production under the conditions of reduced solar irradiance and elevated ozone concentration and other changes in atmospheric. Used open-top chamber (OTC) and black shading network to launch a fumigation level and two kinds of irradiance reduction degree. (field: CK, T1: shading 20%, T2: shading 40%, T3: 100nL/L O3 concentration, T4: 100nL/L O3 concentration and shading 20% compound, T5: 100nL/L O3 concentration and shading 40% compound). The results showed that contrasting to CK, the Fv/Fm(PSⅡ maximum quantum yield), L(PFD) (the relative limit of Photosynthetic function) of T1 treatment are similar and had no obvious changes, but the Yield, qP(Photochemical quenching coefficient), Y(NO) (the non regulation of energy dissipation in quantum yield), (1-qP)/NPQ(Light quantum excess degree) are decreased by 1.3%-21.5%, 7.5%-21.2%, 14.8%-20.6%, 27.7%-51.4% and NPQ(non photochemical quenching coefficient), Y (NPQ)(regulation of energy dissipation in quantum yield) are increased by 12.0%-31.9%, 53.4%-116%. Fv/Fm of T2 treatment had no significant changes, The Yield, qP, L(PFD), Y(NO), (1-qP)/NPQ were decreased by 13.2%-34.0%, 16.9%-36.2%, 6.8%-8.3%, 2.8%-16.0%, 23.1%-32.7%, The NPQ, Y(NPQ) were increased downby 15.9%-38.2% 39.5%-65.4%. The Fv/Fm, Yield(Optical system II actual photochemical efficiency), qP of T3 treatment were decreased by 11.8%-12.6%, 19.1%-28.0%, 15.6%-43.1%. The L(PFD), NPQ, Y(NPQ), Y(NO), (1-qP)/NPQ increased by 1.1%-7.2%, 20.8%-83.6%, 12.6%-40.3%, 3.9%-22.2% obviously, 0.6%-34.1%. Fv/Fm, L(PFD) of T4 treatment were similar to CK and compared with CK, the Yield, qP, Y(NO), (1-qP)/NPQ decreased by 12.7%-42.8%, 7.2%-14.4% 18.8%-27.5%, 16.4%-45.1% and NPQ, Y(NPQ) increased by 13.4%-45.2% 6.9%-110.8%. Fv/Fm, Yield, qP, L(PFD), Y(NO), (1-qP)/NPQ of T5 treatment compared with CK, decreased by 30.4%-50.9%, 27.7%-43.2%, 2.2%-4.9%, 2.2%-10.2%, 23.3%-26.2%, 47.1%-61.6% and NPQ, Y(NPQ) increased by 27.5%-51.6% 63.3%-142.7%. Those results showed that (1) the single factor of Ozone significantly changed photosynthetic activity and distribution of light energy of winter wheat leaves but the single factor of reduced solar radiation alleviated negative effect photosynthesis restriction of winter wheat to a certain extent. (2) Further, under the combined stress, the light energy of winter wheat distributed more to regulatory heat dissipation. Composite action enhanced obviously the heat dissipation capability of winter wheat Radiation attenuation effect could cause winter wheat at the ozone stress self-regulated to better adapt to the adverse environment. Reducing appropriate the amount of solar radiation under Ozone stress could alleviate and reduce the light injury of winter wheat leaves. (3) Reducing solar radiation under the Ozone stress could inhibition the light injury and ensure the winter wheat optical system function normally and the normal growth of Winter Wheat. (4) In spite of winter wheat on composite stress has a certain ability to adapt; the reduced solar irradiance and elevated ozone concentration are still an important issue facing national grain production.

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