臭氧污染对水稻生长、产量及矿质金属元素含量的影响

地表臭氧(O_3)浓度升高造成的空气污染是日渐关注的重要环境问题,既直接危害人体健康,也影响农业生态系统,威胁农作物的生长发育和农产品品质,其中矿质金属元素含量由于同时涉及微量营养元素和有害重金属而尤为重要.本研究开展了O_3浓度升高处理(维持100 nL·L~(-1))的开顶箱(OTC)田间试验,通过2个水稻品种的作物生长监测和采样分析比较,探讨了O_3污染对水稻生长、产量及籽粒矿质金属元素含量的影响.结果表明,高浓度O_3抑制了南粳5055和扬稻6号两种水稻叶片的光合作用并降低了叶绿素含量和叶面积指数,进而导致稻谷产量下降,与自然空气对照相比分别减产45.5%和28.6%;但收获籽粒的糙米和颖壳中大部分矿质金属元素含量升高,与对照相比增幅分别达3.6%～19.8%和3.9%～36.0%,因而由此导致的微量元素缺乏或重金属污染等相关粮食品质安全影响需要综合评价.

Effects of Ozone Pollution on Growth, Yields, and Mineral Metallic Element Contents of Paddy Rice

The increase in the surface ozone (O₃) concentration causes air pollution, which has become a significant environmental issue that is of increasing concern. Ozone pollution not only directly harms human health, but also influences the agricultural ecosystem by impacting crop growth, which may then indirectly affect human health through food quality and the safety of agricultural products. The effects of O₃ pollution on rice growth, yields, and mineral metal contents in grains were investigated through field experiments with increased O₃ concentration treatment (remaining at 100 nL·L^-1) in open top chambers (OTC). The crop growth and metal contents of two rice varieties were analyzed and compared. The results showed that the higher O₃ concentration inhibited the photosynthesis of Nanjing 5055 and Yangdao 6 rice leaves, reduced the chlorophyll content and leaf area index, and subsequently led to a decline in the rice yield of 45.5% and 28.6%, respectively. However, compared with the natural control, the contents of most mineral metallic elements in the brown rice and glume of the harvested grains increased by 3.6%-19.8% and 3.9%-36.0%, respectively, thus resulting in a lack of essential trace elements or pollution of heavy metals; hence, the impact of O₃ on rice food quality and safety requires a comprehensive evaluation.