水稻灌浆期臭氧暴露对产量形成的影响

利用田间原位开顶式气室(Open-topchamber,OTC)研究了长江三角洲地区水稻灌浆期臭氧(O3)暴露对其产量形成的影响,从而确定灌浆期臭氧胁迫对水稻产量的影响.实验设计4种臭氧水平,即过滤空气(CF,O3浓度10nL·L-1);自然大气(NF,O3浓度40nL·L-1);臭氧动态1(O1,O3梯度为50、100、150nL·L-1,平均浓度70nL·L-1);臭氧动态2(O2,O3梯度为75、150、300nL·L-1,平均浓度170nL·L-1).结果表明,随着臭氧浓度的升高,水稻的株高、穗长、分支、穗粒数及水稻生物量和产量等指标均有下降的趋势,但4种处理间均无显著性差异(p>0.05).在试验浓度下,水稻灌浆期短期高浓度O3暴露对其产量没有显著影响,不会造成明显的产量损失,但与全生育期相比,水稻产量对灌浆期的高臭氧浓度更为敏感.

Effects of Ozone on Production of Rice (Oryza sativa L.) during Grain Filling Stage

Effects of ozone on rice yield was studied during grain filling stage using the open-top chamber (OTC). There were four treatments: CF (average ozone: 10nL·L-1); NF (average ozone: 40nL·L-1); Dynamic ozone treatment 1 (O1, concentration gradient: 50, 100, 150nL·L-1, average ozone: 70nL·L-1); Dynamic ozone treatment 2 (O2, concentration gradient: 75, 150, 300nL·L-1, average ozone: 170nL·L-1). The results showed that with the increasing of ozone concentration, the parameters decreased gradually including the height, spike length and grain numbers of rice, but the influence of ozone was not significant (p>0.05). The biomass and yield of rice decreased with the increasing of ozone concentration, but the decrease was also not significant (p>0.05). The seed weight per spike under ozone fumigation was 10% and 16.3% lower than that of CF, respectively; and the yield was 7% and 9% lower than that of CF. Although short term high ozone concentration had no significant effect on rice yield in the Yangtze River Delta, the yield was sensitive to high ozone concentration during grain filling stage.