中文摘要：

近地层臭氧（O3）污染会危害植物生长,势必间接影响氮素吸收利用.本研究利用开放式臭氧污染（Free-air O3 conc entration enrichment,O3 FACE）研究平台,研究了大气O3浓度增加（比周围大气高50%）对长江三角洲地区5个冬小麦（Tritcium aestivum L.）主栽品种（扬麦15、扬麦16、烟农19、扬幅麦2号和嘉兴002）的物质积累、氮素吸收与分配的影响.结果显示,O3浓度升高对秸秆和籽粒的影响远大于根系.烟农19、嘉兴002和扬麦16的产量因O3浓度升高而减少,而扬麦15和扬幅麦2号产量则变化不大.扬幅麦2号与嘉兴002的秸秆干物重因O3浓度升高而显著增加,扬麦15与烟农19分别呈增大与降低趋势,而扬麦16则无变化.表明O3污染对小麦干物质积累与分配的影响存在品种差异.O3浓度升高影响氮素在小麦根、秸秆和籽粒中的含量与分配趋势,但影响程度因品种而异.O3浓度升高导致扬幅麦2号的总吸氮量显著增加30.6%及烟农19的总吸氮量呈增加趋势,并使嘉兴002的总吸氮量显著降低34.8%及扬麦16总吸氮量呈降低趋势,但扬麦15的总吸氮量则不受影响.除扬麦15外,O3浓度升高具有减少籽粒氮占总氮比例的趋势,表明小麦响应O3污染对氮素吸收与分配调整机制存在品种差异.扬麦16、烟农19和嘉兴002的氮肥偏生产力因O3浓度升高而显著降低,而扬麦15和扬幅麦2号则无明显变化.扬麦16和嘉兴002的氮肥利用率因O3浓度升高显著降低,而扬幅麦2号呈增加趋势,扬麦15、烟农19呈降低趋势.综合来看,小麦扬麦15抗O3污染能力强于其它品种,而嘉兴002则最易遭受臭氧污染危害.评价O3污染对小麦干物质与产量的形成与分配、氮素在植物-土壤系统周转的影响应综合考虑品种差异.

英文摘要：

Tropospheric ozone （O3） pollution harms plant growth, which indirectly influences absorption and utilization of nitrogen.Effects of elevated atmospheric ozone （pO3） （50% higher than the ambient pO3） on the biomass and nitrogen uptake and distribution of five modern cultivars of wheat （Tritcium aestivum L.cv.Yangmai 15 （Y15）, Yangmai 16 （Y16）, Yannong 19 （YN19）, Yangfumai 2 （YF2） and Jiaxing 002 （JX002） ） were investigated in fully open-air field conditions in Yangtze River delta.Results showed that straw and grain responded to elevated pO3 more significantly than root.The yield of YN19, JX002 and Y16 decreased, while that of Y15 and YF2 did not show any change in elevated pO3.Elevated pO3 significantly increased the straw biomass of YF2 and JX002 while it had no effect on Y16 and Y15; increasing and decreasing trends in Y15 and YN19, respectively, were also observed.In summary, the response of accumulation and distribution of dry matter to pO3 pollution differed within cultivars.Meanwhile, the N content and distribution were altered by elevated pO3 and the responses also varied among cultivars.The total amount of nitrogen uptake in YF2 significantly increased by 30.6% and the positive effect of elevated pO3 also existed in YN19.Elevated pO3 significantly decreased the total nitrogen accumulation in JX002 by 34.8% and a decreasing trend was observed in Y16, but not in Y15.Except Y15, all the other cultivars showed a decreasing trend in the proportion of nitrogen accumulation in grain with respect to that in total plant.Elevated pO3 remarkably decreased the partial productivity of nitrogen fertilizer in Y16, YN19 and JX002, but had no significant effect on Y15 and YF2.Compared to ambient pO3, the utilization efficiency of fertilizer nitrogen significantly decreased in Y16 and JX002, and slightly increased and decreased in YF2 and in Y15 and YN19, respectively, under elevated pO3.It is concluded that wheat Y15 had the largest potential to resist O3 pollution and wheat JX002 was th