用旋转布气法开顶式气室研究臭氧对水稻生物量和产量的影响

Effects of Elevated Ozone on Biomass and Yield of Rice Planted in Open-Top Chamber with Revolving Ozone Distribution

在开顶式气室(open top chamber,OTC)内,检测了旋转布气法的气体交换效能和对O3分布的均匀性及稳定性,研究了O3体积分数升高对水稻(Oryza sativaL.)光合速率、生物量和产量的原位影响.经实验检测,旋转布气法能使O3在OTC内分布比较均匀、稳定,满足OTC内布气要求,使气室内外最大温差为1.87℃;同时实验还表明O3体积分数的升高减少了水稻叶片光合速率、抑制了生物量的累积和降低了水稻的产量.在O3体积分数为1×10-7和2×10-7暴露下,水稻叶片光合速率分别比对照降低38.6%和53.9%,地上生物量累积速率分别降低8.8%和32.3%,产量分别降低10.1%和53.1%.结果表明,该旋转布气方法性能稳定,可广泛用于大气特定成分变化对近地层生态系统的原位影响研究.

Improved open-top chamber （OTC） by revolving ozone distribution has been established for studying the effects of elevated ozone on photosynthesis, biomass and yield of rice （ Oryza sativa L. ）. The result showed that the improved OTC could distribute ozone equably and stably in OTC and meet the need of air exchanging between inside and outside OTC. The difference in temperature between inside and outside of OTC was less than 1.87℃. The experiment also suggested that elevated ozone could decrease photosynthetic rate of flag leaves, biomass and yield of rice. Compared with control,photosynthetic rates of rice flag leaves exposed to 1 ×10^-7 and 2 ×10^-7 O3 were decreased by 38.6% and 53.9% respectively, during 10：00- 11：00 on a sunny day in grain filling stage. In comparison with control,the relative growth ratios （RGR） of aerial biomass of rice plant exposed to 1 ×10^-7 and 2 ×10^-7 reduced by 8.8% and 32.3% ,respectively. In the end,exposures to 1 ×10^-7 and 2 ×10^-7 O3 resulted in yield losses by 10.1% and 53.1% ,respectively.