• 关键词：铅  丁草胺  油麦菜  酶活性  交互作用

• 基金项目：河南省自然科学基金项目 (No. 092300410114)

• 刘文霞
• 河南农业大学环境系,郑州 450002

• 郭华武
• 河南农业大学环境系,郑州 450002

• 李博
• 河南农业大学环境系,郑州 450002

• 沈连峰
• 河南农业大学环境系,郑州 450002

• 摘要：盆栽土培试验研究了重金属铅与除草剂丁草胺的复合污染对油麦菜生长及生理生化的毒性效应.结果表明土壤铅浓度小于500 mg·kg^-1对油麦菜发芽率的影响不明显,铅浓度为150 mg·kg^-1对油麦菜株高有促进作用,但对叶片过氧化物酶(POD)和过氧化氢酶(CAT)活性有明显抑制作用.土壤铅浓度为500 mg·kg^-1时,油麦菜根活性、叶片POD和CAT酶活性较对照明显降低,铅浓度越大,根活性和叶片酶活性越低.丁草胺浓度为2~6 mg·kg^-1 时油麦菜发芽率明显降低,丁草胺浓度增加,油麦菜株高、生物量、根重和根活性受到抑制作用愈大,叶片POD和CAT酶活性越低.低浓度(Pb²⁺ 150 mg·kg^-1 和丁草胺2 mg·kg^-1)和高浓度(Pb²⁺ 500 mg·kg^-1 和丁草胺6 mg·kg^-1)复合污染浓度越大,油麦菜发芽率越低,对油麦菜的抑制作用为根重>生物量>叶片POD酶>CAT酶>根活性,但对叶片叶绿素的合成有促进作用.低浓度铅与丁草胺的交互作用对生物量抑制表现为协同作用,根活性、CAT酶和POD酶活性抑制均为拮抗作用.高浓度铅与丁草胺的交互作用对油麦菜株高、生物量和根活性的抑制为协同作用,对CAT酶和POD酶活性抑制为拮抗作用,而铅与丁草胺的交互作用对叶绿素的合成有协同效应.

• Abstract：The pot experiment was conducted to study the toxic effects of combined pollution of Pb²⁺ and butachlor on the growth and physiology of Lactuca sativa L. The results indicated that germination rates of L. sativa were not obviously affected when the Pb²⁺ concentration was below 500 mg·kg^-1. With the concentration of added Pb²⁺ of 150 mg·kg^-1, the plant height was increased, but activities of peroxidase (POD) and catalase (CAT) in leaves were evidently inhibited. When the concentration of added Pb²⁺ reached 500 mg·kg^-1, the root vitality and POD and CAT activities in leaves were inhibited; the inhibition effect was enhanced when the Pb²⁺ concentration was increased. Experiments with butachlor at concentrations of 2~6 mg·kg^-1 showed inhibition effects on plant height, biomass, root weight and vitality, and POD and CAT activities in leaves. Further experiments with combination of two pollutants showed lower germination rates of L. sativa when the concentration of complex pollution was increased. At both low and high concentrations, the root weight of L. sativa was most severely inhibited and the root vitality was least affected, but the chlorophyll content in leaves was increased. Pb²⁺ and butachlor at low concentrations had synergistic effects on the inhibition of biomass and antagonistic effects on the inhibition of root vitality, POD and CAT activities. However, at high concentrations, the two pollutants had synergistic effects on inhibition of plant height, biomass and root vitality, and antagonistic effects on inhibition of POD and CAT activities. Additionally, Pb²⁺ and butachlor demonstrated synergistic effects on chlorophyll biosynthesis.

• Key words：Pb²⁺  butachlor   Lactuca sativa L.  enzyme activity  interaction effect

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