邻苯二甲酸二甲酯(DMP)对黄瓜抗氧化代谢及果实品质的影响

Toxic effects of dimethyl phthalate on cucumber at the growth stage

以黄瓜(Cucumis sativus L.)为材料,通过分析邻苯二甲酸二甲酯(DMP)处理对黄瓜成株叶片中抗氧化酶活性、脯氨酸含量、丙二醛含量、果实品质的影响及DMP在黄瓜体内的积累情况,研究DMP对黄瓜的生态毒性效应。结果显示:30 mg·L^(-1)的DMP处理下叶片抗氧化酶活性增加,果实营养价值降低,但黄瓜植株生长及干物质积累变化不大;50 mg·L^(-1)处理下,叶片抗氧化酶在盛花期达到最大值,随着处理时间延长黄瓜叶片的抗氧化酶活性、干物质积累及营养价值均降低;而100和200 mg·L^(-1)处理下的黄瓜叶片,抗氧化酶活性始终低于对照处理组的水平,干物质积累随着DMP处理浓度增加呈下降趋势,且果实均在幼果期出现萎蔫致死现象;DMP在黄瓜植株内的积累量随其浓度升高而增加(茎>根>叶)。上述结果表明,DMP污染会影响黄瓜正常的生理生化指标,降低黄瓜果实的品质,会产生潜在的健康风险。

The leaves of cucumber（Cucumis sativus L.）were used to study the effects of dimethyl phthalate（DMP）on antioxidant enzyme activities and proline（Pro）and malondialdehyde（MDA）content. Furthermore, the fruit quality and the accumulation of DMP were studied to investigate the ecological toxic effects of DMP on cucumber. The results showed that the activities of antioxidant enzymes in the leaves treated with 30 mg·L^-1 DMP were increased, with a decrease in the nutritional value of the fruit. However, this had a very little impact on the accumulation of dry matter and plant growth. Under the treatment of 50 mg·L^-1 DMP, the antioxidant enzyme activities of the leaves achieved their peak value at full-blooming stage. The antioxidant enzyme activities, the accumulation of dry matter, and the fruit nutritional value all declined with increasing treatment time. However, under the treatments of 100 mg·L^-1 and 200 mg·L^-1 DMP, the antioxidant en-zyme activities were remarkably suppressed（P〈0.05）as compared to those of the control group during the entire growth period. Moreover, with increasing concentration of DMP, a decline in the accumulation of dry matter was presented, with the appearance of a fatal wilting phe-nomenon during the young fruit period. The accumulation of DMP in the cucumber increased with increasing concentrations（stem〉root〉leaf）. These results showed that DMP pollution could affect the normal physiological and biochemical indices of cucumber, reduce the quali-ty of cucumber fruit, and hence pose potential health risks.