Division of Environmental and Agricultural Engineering, Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo, 183-8509, Japan.
Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan.
Environ Sci Pollut Res Int. 2019 Nov;26(31):32103-32113. doi: 10.1007/s11356-019-06358-6. Epub 2019 Sep 7.
To examine whether the sensitivity of growth and yield of rice (Oryza sativa L.) to ozone (O) varies under different nitrogen (N) fertilization conditions, rice cultivar 'Koshihikari' was exposed to O under either standard N (SN) fertilization or no N (NN) fertilization. The rice plants were subjected to three gas treatments (charcoal-filtered air (CF) and O at 1.0 (1.0×O) and 1.5 (1.5×O) times the ambient concentration) in combination with two conditions of N fertilization. At five time points throughout the growth period, plant samples were collected to measure the leaf area and dry mass of each plant organ. At the final harvest, yield, yield components, and harvest index were measured. There was a significant interactive effect of O and N on leaf, stem, root, and whole-plant dry mass at the final harvest. The dry mass of each plant organ and the whole-plant dry mass of rice plants grown in 1.5×O were significantly lower than those in the plants grown in CF and 1.0×O under SN, whereas there were no significant differences in the dry mass among the three gas treatments under NN. Brown rice yield was significantly reduced by the exposure to O under SN, but not under NN. Relative yield loss rate based on the AOT40 (accumulated exposure over a threshold of 40 nmol mol) was pronounced under SN, whereas relative yield was almost unchanged at different AOT40 levels under NN. We concluded that the sensitivity of growth and yield of rice to O is dependent on N levels in the soil; the exposure to ambient levels of O has a negative effect on rice under SN, but not under NN.
为了研究在不同氮（N）施肥条件下，水稻（Oryza sativa L.）的生长和产量对臭氧（O）的敏感性是否存在差异，本研究以水稻品种“越光”为材料，在标准氮（SN）施肥或不施氮（NN）条件下，将水稻暴露于臭氧中。将水稻植株置于三种气体处理（木炭过滤空气（CF）和臭氧浓度分别为环境浓度的 1.0 倍（1.0×O）和 1.5 倍（1.5×O））和两种氮施肥条件下。在整个生长期间的五个时间点采集植物样本，以测量每个植物器官的叶面积和干重。在最终收获时，测量产量、产量构成和收获指数。在最终收获时，臭氧和氮对叶片、茎、根和整株干重存在显著的交互作用。在 SN 下，1.5×O 中各植物器官的干重和整株干重均显著低于 CF 和 1.0×O 中的干重，而在 NN 下，三种气体处理之间的干重没有显著差异。在 SN 下，臭氧暴露显著降低了糙米产量，但在 NN 下没有。基于 AOT40（超过阈值 40 nmol mol 的累积暴露量）的相对产量损失率在 SN 下明显，而在 NN 下，不同 AOT40 水平下的相对产量几乎没有变化。综上所述，水稻对臭氧的生长和产量敏感性取决于土壤中的氮水平；在 SN 下，大气中臭氧浓度的增加对水稻有负面影响，但在 NN 下则没有。
