【作者】 赵广琦；

【导师】 王勋陵；

【作者基本信息】 西北大学 ， 生物学， 2003， 博士

【摘要】 臭氧层减薄引起的太阳紫外线-B（UV-B，280-320nm）辐射增强和环境破坏导致的大气CO₂浓度升高对生物圈的影响已越来越引起人们的关注。增强的UV-B辐射和CO₂浓度升高都会直接或间接影响植物的生理、形态结构和生长发育过程。以往的研究大多只重视其中的单一因子效应，而对二者的复合效应的研究十分有限。本文在室外控制条件下运用植物生理学和生态学方法研究了增强的UV-B辐射和CO₂倍增的复合作用对蚕豆、小麦生长发育和生理生态的影响。结果表明： （1）CO₂倍增降低了蚕豆和小麦对增强UV-B辐射的敏感性。在CO₂倍增条件下，小麦对增强UV-B辐射的抗性大于蚕豆。 （2）在增强UV-B辐射和CO₂倍增复合处理下，蚕豆和小麦生长节律正常。而在增强UV-B辐射下，蚕豆和小麦生长和发育滞后，生育期延长，物候推迟；在CO₂倍增下，蚕豆和小麦的生长和发育加速，生育期缩短，物候提前。 （3）当增强UV-B辐射和CO₂倍增复合处理时，蚕豆和小麦的株高与对照基本一致。而增强UV-B辐射使蚕豆和小麦株高降低，降幅随发育进程增大；CO₂倍增使蚕豆和小麦的株高增加，增幅随发育进程增大。相比之下，增强UV-B辐射对小麦株高影响较大，CO₂倍增对蚕豆株高影响较大。 （4）增强UV-B辐射和CO₂倍增复合处理基本不改变蚕豆和小麦的生物量。而增强UV-B辐射使蚕豆和小麦生物量下降，降幅随发育期有所不同；CO₂倍增使蚕豆和小麦生物量均有明显增加，增幅在地上和地下部略有差异。 （5）增强UV-B辐射和CO₂倍增复合处理下，两种作物产量增减不明显。蚕豆和小麦的产量在增强UV-B辐射下均减少，在CO₂倍增处理下均增加。且UV-B辐射和CO₂对蚕豆产量的影响均大于小麦。 （6）增强UV-B辐射和CO₂倍增复合处理时，蚕豆和小麦产量构成基本不变。而增强的UV一B辐射使蚕豆单株的结荚数、粒数及粒重均显著降低，CO:倍增处理则相反;增强UV一B辐射使小麦的总穗数、总粒数及千粒重显著降低，COZ倍增则相反。 （7）在增强UV一B辐射和COZ倍增复合处理下，蚕豆和小麦的叶绿素和类胡萝卜素含量变化不显著。而增强的UV一B辐射使蚕豆和小麦的叶绿素和类胡萝 卜素含量均下降，CO:倍增使蚕豆和小麦的叶绿素、类胡萝卜素含量均有不同程度提高，且对蚕豆的提高幅度均大于小麦。 （8）增强UV一B辐射和CO:倍增复合处理基本不改变蚕豆和小麦的光合速率。而蚕豆和小麦在增强Uv一B辐射下光合速率降低，在cq倍增下光合速率增高，且随着发育进程，变幅下降。 （9）蚕豆和小麦无论在增强Uv一B辐射、COZ倍增的复合还是单独处理下，其气孔导度均下降，且下降幅度最大的是复合处理，依次是UV一B辐射处理和Cq处理。 （10）在增强UV一B辐射和COZ倍增复合处理下蚕豆和小麦的WUE最大。而UV一辐射使蚕豆和小麦的WUE下降，COZ提高了蚕豆和小麦的WUE。 （11）CO:首先是通过提高紫外吸收物、类胡萝卜素和可溶性蛋白质的含量来增强植物对增强UV一B辐射的防御能力。在UV一B和C02复合处理下，植物的紫外吸收物、类胡萝卜素和可溶性蛋白质含量同样得到提高，因而生长发育正常。 （12）C02其次是通过提高抗氧化酶SOD、POD、CAT的活性和抗氧化物质AsA、GSH的含量来加强植物清除活性氧的能力，防止膜脂质过氧化，从而增强对UV一B辐射的防护作用。因此在UV一B和CO:复合处理下植物具有较高的抗氧化能力，能够进行正常的生理生化代谢。 本研究旨在推动我国对植物响应全球变化中复合效应方面的基础和应用研究，为填补我国UV一B辐射和COZ复合作用对植物影响的研究空白开创道路，为预测植物响应我国未来复杂多变的综合气候条件提供参考。同时亦可为制定在未来气候条件下我国发展农业生产的策略提供科学依据。更多还原

【Abstract】 The effects of enhancement of solar ultraviolet-B(UV-B,280~320 nm) radiation caused by ozone depletion and increasing atmospheric CO2 concentration resulting from environment damage on biosphere have already got comprehensive notes among the government and scientists. Plants growing in enhanced UV-B radiation or elevated CO2 concentration may change with their physiological, morphological structure and the process of growth and development directly or indirectly. Although extensive studies were done about biological and ecological effects of single factor of them, little was known about the combined effect of enhanced UV-B and high CO2. In this paper, influences of enhanced UV-B and doubled CO2 on the growth and development and physioecology of broad bean and wheat were investigated with the method of plant physiology and ecology by using OTC outdoor. The result shows:(1) Doubled CO2 decreased the sensitivity of broad bean and wheat to enhanced UV-B radiation. The resistance of wheat to enhanced UV-B is bigger than that of broad bean, exposed to doubled CO2.(2) Broad bean and wheat exposed to both of enhanced UV-B and doubled CO2 grew normally. Enhanced UV-B could lengthen growing and development period, and phonology is delayed. But doubled CO2, which speeded up the growing and development, made development period shorten, and speeded the phonology.(3) The plant heights of broad bean and wheat under treatment of both enhanced UV-B and doubled CO2 were close to that of control. Enhanced UV-B made theheights lowered, and the lowered extent increased with development process. Doubled CO2 made the heights increased, and the increased extent enhanced with development process. Compared with each other, enhanced UV-B affected plant height of wheat more than that of broad bean, and doubled CO2 affected plant height of broad bean more than that of wheat.(4) The combined effects of enhanced UV-B and doubled CO2 didn’t change fundamentally the biomass of broad bean and wheat. Their biomass declined under enhanced UV-B, the declined extent varied in different development stages. The biomass under doubled CO2 could increase, the increased extent of aboveground biomass was different from that of underground biomass.(5) The combined effects of enhanced UV-B and doubled CO2 didn’t change the yield of broad bean and wheat on the whole. Their yield could also be reduced under enhanced UV-B, and increased under doubled CO2.(6) The yield formation in broad bean and wheat didn’t change basically under treatment of both enhanced UV-B and doubled CO2. Filled grain number per plant, grain number and grain weight of broad bean were decreased by enhanced UV-B, but increased by doubled CO2. Total panicle number, total grain number and 1000-grain weight of wheat were decreased by enhanced UV-B, but increased by doubled CO2.(7) The contents of chlorophyll and carotenoid of broad bean and wheat didn’t change basically under the combined effects of enhanced UV-B and doubled CO2. They were decreased by enhanced UV-B, but increased by doubled CO2. The increased extent in broad bean was bigger than that in wheat.(8) The combined effect of enhanced UV-B and double CO2 didn’t change the photosynthetic rate (Pn) of broad bean and wheat on the whole. Enhanced UV-B decreased Pn, and doubled CO2 enhanced Pn. The change extent declined with developmental process.(9) The stomatal conductance (Gs) of broad bean and wheat could be reduced in any case of each or combined treatment of enhanced UV-B and doubled CO2. The reduced extent of combined stress was the biggest, the effect of CO2 on Gs was less than that of UV-B.(10) The combined effects of enhanced UV-B and doubled CO2 increased WUE greatest. The enhanced UV-B decreased WUE, but doubled CO2 made WUE higher.(11) It was primary response that CO2 was found to be capable to protect plants from UV-B-induced damage by increasing the UV absorbing compounds, carotenoid and soluble protein contents. These were the same under combined treatment, thus plants g更多还原