地表太阳辐射减弱和臭氧浓度增加对冬小麦生长和产量的影响

Combined effects of elevated O_3 and reduced solar irradiance on growth and yield of field-grown winter wheat

为研究辐射减弱和O3胁迫对作物的影响,利用改进的开顶式气室(OTC)和遮荫网,开展了辐射减弱和O3胁迫的大田试验研究。实验设置4种处理:CK为野外大田组,T1为40%遮荫,T2为100 nL/LO3,T3为遮荫40%和100 nL/LO3的复合组。结果表明:T1和T3组冬小麦的生育期延长且推迟,T3组株高无明显变化;T2组株高降低,生育期缩短;单株干物质重均降低,T3降幅最大;各组灌浆速率均降低,T3组降幅最大;T1和T3产量、千粒重、穗数、穗粒数和穗重显著降低,T2组穗数无明显改变。由此可见,复合对小麦生长的影响较接近40%遮荫;粒重降低主要是因为灌浆速率的降低,灌浆时间的影响较小;产量的降低主要是千粒重、穗数、穗重的降低,降幅最大,但小于两因子单独累加。

As a consequence of increases in aerosols,air pollutants and population density,dimming or shading have become major challenges to crop production in China.And during the last several decades,significant increase in the concentrations of tropospheric ozone（O3） have been reported.The increased tropospheric O3 concentrations and induced solar irradiance may concomitantly occur and lead to reductions in yield of crops and economic plants.Especially,there are a great variety large-scale industries in the Yangtze River delta where is the major producting area of winter wheat.Which will enlarge the high-potential risks on growth and yield of winter wheat for their heavy air pollution. Although the influences of each individual stress on plant performance have been widely studied,much less is known about the interactions of O3 stress and solar irradiance on the winter wheat.In order to analysis this focus question in the varied growth stages of crop including jointing stage,booting stage,blooming stage,grain filling stage and mature stage,a experiment based on open top chambers（OTC） was conducted from November 18 of 2010 to June 5 of 2011 in Nanjing University of information Science Technology（32°14′ N,118°42′ E）,located at North suburb of Nanjing,Jiang Su Province.And the YangMai13 as a tested variety was a pillar in our study. Winter wheat are exposed to unfiltered air（CK）,shaded 40% of nature solar irradiance（T1）,enhanced increased O3 concentration（100nL/L O3,T2） and combined treatment（100nL/LO3 ＋shading 40%,T3）.The results are showed as follows： the treatments of T1,T2 and T3 all cause the changes of growth period and the plant premature aging.The grain filling stage and the growth period are all shortened in T2 treatment;T1 and T3 treatments,however,prolong the growth stage of winter wheat.In addition,a significant reduction of dry matter production under T1,T2 and T3 treatments compared to CK（P0.05） with declined 23.37%（P0.05）,35.61%（P0.05） and 55.29%（P0.05）,respectively.Besides,compared with CK,the grain weight、1000-grain weight and ear weight of each treatment are all reduced（P0.05） under the treatments.And it clearly shows that ear number of T1 and T3 are both declined（P0.05）.We can preliminary conclude that compared with shading and O3 alone,the combination between shading 40% and O3 concentration enhanced can enlarge the negative effects on wheat growth and yield.Moreover,the effects of growth and growth period of under the combination are closer to 40% solar irradiance treatment.And the major reason for declined grain weight under the combination is decrease of grain filling rate instead of decreases of grain filling duration.It also obviously demonstrated that the number of spikelet,the grain weight per spike and the 1000-grain weight of the composite treatments decreased significantly（P0.05） 35.15%,39.32% and 34.38%,separately.As a result,the grain yield decreased by 64.65% compared with the control,but the value is less than two factors accumulate alone.