Acid rain is one of the major environmental problems that causes plant morphological and physiological disorders. But there are few studies about the impact of acid rain on vegetable crops. This work aimed to study the various effects of simulated acid rain (SAR) at different levels of pH (5.0, 4.5, 4.0, 3.5 or 3.0) on growth, yield, pigment content, protein, carbohydrate, water content in leaves, minerals (NPK), oxidative damage and the activity of various antioxidants in pumpkin. The results show that the plant growth, yield, chlorophyll, carotenoids, protein, carbohydrates, leaf water content, NPK in the leaves of the pumpkin crop decreased significantly with increasing levels of acidity of SAR as compared to the untreated set. H₂O₂ and MDA are increased by SAR treatment which depends on the level of pH value of SAR. The highest value of hydrogen peroxide and malondialdehyde was recorded at pH 3.0 and lower at pH 5.0 of SAR treatment on the pumpkin crop. In contrast, superoxide dismutase, catalase, nitrate reductase and proline contents were accumulated at pH 3.0 and degraded at pH 5.0 of SAR treatment on pumpkin as compared to control. In conclusion, our findings suggest that pumpkin produces more reactive oxygen species (ROS) scavenging SAR stress through the production of enzyme and non-enzyme antioxidant compounds at 3.0 pH. Meanwhile, growth inhibition as well as the photosynthesis of pumpkin and the magnitude of oxidative damage increased as acidity increased (pH 3.0 of SAR).

酸雨是引起植物形态和生理紊乱的主要环境问题之一。但关于酸雨对蔬菜作物影响的研究较少。本工作旨在研究模拟酸雨 (SAR) 在不同 pH 值（5.0、4.5、4.0、3.5 或 3.0）下对生长、产量、色素含量、蛋白质、碳水化合物、叶片中的水分含量、矿物质（ NPK)、氧化损伤和南瓜中各种抗氧化剂的活性。结果表明，与未处理组相比，随着 SAR 酸度水平的增加，南瓜作物叶片中的植物生长、产量、叶绿素、类胡萝卜素、蛋白质、碳水化合物、叶片含水量、NPK 显着降低。H ₂ O ₂和 MDA 通过 SAR 处理增加，这取决于 SAR 的 pH 值水平。南瓜作物上过氧化氢和丙二醛的最高值记录在 pH 3.0 和 SAR 处理的 pH 5.0 时较低。相比之下，与对照相比，超氧化物歧化酶、过氧化氢酶、硝酸还原酶和脯氨酸含量在 pH 3.0 时积累，并在 SAR 处理的 pH 5.0 下降解。总之，我们的研究结果表明，南瓜通过在 3.0 pH 值下产生酶和非酶抗氧化化合物来产生更多的活性氧 (ROS) 清除 SAR 应激。同时，随着酸度的增加（SAR的pH 3.0），南瓜的生长抑制以及光合作用和氧化损伤的程度增加。