[Objective]In recent years, tropospheric (ground level) ozone concentration was growing year by year because of the development of agriculture and industry, and had generated a degree of damage on crop production.[Method]The effects of elevated ozone concentration (O3) on grain yield and its components and grain plumpness in five varieties of winter wheat (Tritcium aestivum L.) with a FACE (Free-Air Controlled Environment) system were studied in 2007-2009.The main-plot treatment had two levels of (O3): ambient level (A-O3) and 50％ higher than ambient level (E-O3), and the sub-plot treatment had five typical varieties:Yannong 19, Yangmai 16, Jiaxin 002, Yangmai 15 and Yangfumai 2.The ozone treatment was imposed upon for the period from 5 March to 26 May in 2008 and from 6 March to 24 May in 2009, respectively.[Result]The O3 elevation decreased grain yield and its components (grain weight and numbers) significantly or very significantly.Under E-O3, the average grain yield was decreased by 19.74％ (10.06％-34.53％) in two years, and 1000-grain-weight decreased by 17.88％ (10.16％-29.47％), grain number per ear decreased by 3.47％ (-1.53％-11.90％), but ear number increased by 0.95％ (-14.58％-23.74％) in different varieties, respectively.There was a significant or very significant difference among treatments, cultivars and years.The O3 elevation affected the development process of wheat grains, the grain length, width and thickness were decreased by 0％-4.16％, 7.95％-20.24％ and 2.66％-11.00％ under E-O3 condition, which led to the decrease of grain volume by 8.5％-31.5％.The O3 elevation affected grain filling process, the average grain filling rate decreased.Because of the changes of grain volume and grain weight, grain plumpness degree changed by -21.40％-3.76％, the grain shrinkage index increased by 0.23％-36.66％, respectively.[Conclusion]Under E-O3,grain yield decrease resulted mainly from the declining of grain weight which was caused by the decrease of grain filling rate and grain plumpness.%[目的]探讨近地层大气O3浓度增高对小麦生产的影响.[方法]2007-2009年度应用FACE研究平台,以O3自然浓度(A-O3)为对照,设计O3浓度增高50%(E-O3)进行对比试验,采用烟农19、扬麦16、嘉兴002、扬麦15和扬辐麦2号等5个品种为对象,研究大气O3浓度增高50%对不同基因型小麦品种籽粒产量及其构成因素的影响.[结果]O3浓度增高显著降低小麦籽粒产量,降幅为10.10%-34.51%,平均为19.74%,品种、年度间存在显著或极显著差异.O3浓度增高条件下千粒重降低17.88%(10.16%-29.47%);每穗粒数下降3.47%(-1.53%-11.90%),但穗数平均较对照增加0.95%(-14.58%-23.74%),处理、品种和年度间存在显著或极显著差异.O3浓度增高50%使籽粒长、宽、厚和籽粒体积分别减小 0-4.16%、7.95%-20.24%,2.66%-11.00%和8.5%-31.5%;皱缩指数增大0.23%-36.66%,籽粒灌浆速率降低,籽粒充实度变化为-21.40%-3.76%,最终导致粒重降低.[结论]FACE条件下O3浓度增高使籽粒灌浆物质来源不足,籽粒库容变小,充实度降低,粒重变小,最终导致小麦籽粒产量下降.
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