【作者】 孙健；

【导师】 郑有飞；

【作者基本信息】 南京信息工程大学 ， 环境科学， 2012， 硕士

【摘要】 目前气溶胶的辐射效应是众多学者关注的焦点,太阳辐射减弱通过直接或间接作用影响并造成作物光合能力下降,进而导致作物减产；而在未来环境变化背景下,地表03浓度呈持续增加趋势,O3对作物的生长发育及代谢过程都有强烈的负面效应,直接威胁粮食作物的安全。为进一步探明地表O3浓度增加和大气气溶胶所产生的太阳辐射减弱效应对农作物光合能力及荧光特性的影响机制,本研究采用完全随机分组的方法,在大田试验条件下,设置了(CK, OTC不通臭氧不加遮光网)、T1(80%自然光)、T2(60%自然光),T3(40%自然光)和T4(通100nL·L-1O3),T5(80%自然光和通100nL·L-1O3),T6(60%自然光和通100nL·L-1O3),T7(40%自然光和通100nL·L-1O3)8个不同太阳辐射减弱和高浓度臭氧处理,对大田生长的冬小麦进行太阳辐射减弱和臭氧熏气处理,较为系统的研究了太阳辐射减弱和高浓度O3对冬小麦光合作用、荧光参数、光响应曲线的影响作用,为防治太阳辐射减弱和高浓度O3对我国农业生产的影响提供科学依据。主要结论如下：(1)O3浓度增加和太阳辐射减弱显著降低了生长前期各处理组冬小麦叶片中光合色素含量,而增加了冬小麦叶片耗散色素尤以叶黄素的含量增加最明显,更好地通过增加叶黄素循环以在逆境中适应性生长。(2)太阳辐射减弱和高浓度臭氧均显著降低了各处理组的光合速率(Rn)、Gs、Ls,而各处理组的Ci较CK显著升高。拔节期T1-T2处理组的WUE较CK升高显著,T3-T4较CK显著降低；抽穗期T1-T3较CK显著升高,T4较CK降低。T5-T7处理组的WUE在拔节期和抽穗期较CK均显著增大。以上表明,太阳辐射减弱单因子和高浓度O3同时作用均显著降低了生长前期冬小麦的光合能力,但不同程度地增加了WUE；高浓度O3明显抑制了冬小麦叶片的WUE。(3)太阳辐射减弱和高浓度臭氧降低了qP、Y(NO)、实际光量子效率(Yield)、初始斜率、Ik,而(1-qP)/NPQ、NPQ和Y(NPQ)较CK显著升高。可见,太阳辐射减弱和高浓度臭氧胁迫下冬小麦叶片会下调PSⅡ原初光化学反应的电子传递效率来适应光能不足的逆境胁迫(光化学猝灭系数qP的下降),同时增加叶片热耗散能力(叶黄素循环增加、NPQ和Y(NPQ)显著升高)适应逆境。在臭氧胁迫下太阳辐射减弱对冬小麦叶片的光合色素、净光合速率和蒸腾速率等的影响起到主导地位。(4)太阳辐射强度减弱和高浓度臭氧胁迫下冬小麦叶片吸收的光能分配方向也发生显著的变化,T1-T4处理组较CK吸收的光能逐渐由D转向E,而T5-T7由E转向D部分以更好地适应逆境。更多还原

【Abstract】 Aerosol is currently one of the major environmental issues of concern to the world, and atmospheric aerosol through direct or indirect effects to affect crop photosynthetic capacity decreased, which led to the reduction of crop yield; But in the context of environmental change in the future, the surface concentration of O3showed a continuous increase trend has strong negative effects on crop growth and metabolic process, which will be a direct threat to the food crops security. In order to further prove the effects increase in surface O3concentration and atmospheric aerosols generated by solar radiation attenuation on crop photosynthesis and fluorescence characteristics of impact mechanism. This study, in the field experiment conditions by using a completely randomized grouping method, set (CK, OTC without ozone and shading net), T1(80%natural light), T2(60%natural light), T3(40%natural light) and T4(100nL·L-1O3), T5(80%natural light and100nL·L-1O3), T6(60%natural light and100nL·L-1O3), T7(40%natural light and100nL·L-1O3)8different reduced solar radiation and high concentrations of ozone treatments. On the growth of Winter Wheat in field weakening solar radiation and ozone fumigation treatments, systematic research the effects of the solar radiation attenuated and high concentration of O3on winter wheat photosynthesis, chlorophyll fluorescence parameters, light response curve effect and mechanism for the prevention and control of atmospheric aerosols and high concentration of O3on agricultural production in China and provide scientific basis. Main conclusions are as follows:(1)The increased O3concentration and reduced solar radiation significantly reduced photosynthetic pigment content in winter wheat leaves in each treatment group at the growth stage, and increased dissipation pigment especially lutein increased obviously, to better adaptive growth by increasing the xanthophyll cycle in adversity.(2)Reduced solar radiation and high O3concentration significantly decreased photosynthetic rate (Pn), Gs, Ls, in each treatment group but Ci in each group was significantly elevated contrasted to CK. the WUE of T1-T2treatment groups were higher than CK in the jointing stage and T3-T4significantly reduced; In heading stage T1-T3significantly increased contrast to CK, T4was lower than CK. WUE of T5-T7treatments in jointing and heading stage were significantly increased compared with CK. The above shows, reduced solar radiation and high concentration of O3all significantly reduced winter wheat photosynthetic capacity in early growth period, but increased the WUE at different degrees. High concentration O3significantly inhibited the WUE of Winter Wheat Leaves.(3)Reduced Solar radiation and high concentration ozone decreased qP, Y (NO), the actual light quantum efficiency (Yield), initial slope, Ik, but the (1-qP)/NPQ, NPQ and Y (NPQ) significantly increased compared with CK. Under the stress of solar radiation attenuation and high concentration ozone, winter wheat leaves would by PSⅡ primary photochemical reactions of electron transfer efficiency to meet the energy deficiency stress (photochemical quenching coefficient qP decline), while increasing the heat dissipation capabilities (leaf xanthophyll cycle increased, NPQ and Y (NPQ) significantly increased adapt to adversity.(4) The absorbed light energy distribution direction in winter wheat leaves also produced marked change under the stress of reduced solar radiation and high concentration ozone. Light energy which T1-T4treatments group absorp shifted from D to E, but T5-T7treatments group gradually shifted from E to D in order to better adapt to adversity.更多还原