Effects of Ozone on Production of Rice (Oryza sativa L.) during Grain Filling Stage
水稻灌浆期臭氧暴露对产量形成的影响

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.