FACE条件下O3浓度增高对小麦产量和籽粒充实的影响

 【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。

Effects of Elevated Ozone Concentration on Grain Yield and Plumpness in Wheat with FACE System

【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.