2014 年 70 巻 4 号 p. 213-222
Air pollutant concentrations such as ozone (O3) and peroxides have been increasing in the world, and may cause many negative impacts on crop production. The objectives of the present study are to investigate the effects of peroxides and O3 on visible foliar injury and physiological responses, and to compare the sensitivities among two Thai rice cultivars, RD 31 and Chainat 1, and two Japanese rice cultivars, Nipponbare and Nourin 52, under exposure to single O3 and combined O3 and peroxides. Four treatment plots were prepared, namely control plot (O3 2-3 ppbv and free peroxides), O3 50 ppbv plot and free peroxides, O3 50 ppbv and peroxides 3 ppbv plot and O3 50 ppbv and peroxides 5 ppbv plot. The results showed that combined O3 and several ppbv peroxides plots caused severe damage on visible leaf injury, increase in Malondialdehyde (MDA) concentration, and decrease in total chlorophyll content and a net photosynthetic rate much higher than single O3 plot. According to the O3 dose response analysis, we found that, in combined O3 (50 ppbv) and peroxides (3 ppbv and 5 ppbv) exposure, in case of visible foliar injury, Chainat 1 was seriously damaged rice cultivar while Nipponbare was a less damaged rice cultivar.
