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为明确在农药和重金属复合污染条件下烟草根系发育的响应,利用室内盆栽试验,系统研究了烟草根系发育及其生理生化指标对杀菌剂甲霜灵和重金属镉在单一及复合污染胁迫的响应.研究结果表明:添加20 mg/kg甲霜灵对烟草主根长、根体积和根系活力均有显著促进作用,而对根干物质重产生抑制作用;添加20 mg/kg镉对烟草主根长和根干物质重产生显著抑制作用,对根体积有刺激作用,对根系活力则有先促进后抑制作用;甲霜灵与镉复合污染对烟草主根长和根干物质重有显著抑制作用,主根长和根干物质重与CK相比分别减少23.20％和31.57％,其对根体积有刺激作用,对根系活力则有先促进后抑制作用,而且重金属镉的添加抑制了烟草根系对于甲霜灵的吸收与转运.烟草根系发育对甲霜灵与镉单一及复合污染的响应将为今后植烟土壤中农药与重金属复合污染风险评估提供重要依据,同时也对复合污染的修复及改良具有重要意义.“,”In order to clarify the response of tobacco root development to combined pollution of pesticides and heavy metals, the research systematically studied the responses of tobacco roots development and its physical and biochemical indexes under single and combined pollution by bactericide metalaxyl and heavy mental cadmium using an indoor pot experiment. The results showed that 20 mg/kg metalaxyl addition had significant effects on the main root length, root volume and root activity of tobacco, but it had a certain inhibitory effect on root dry matter weight. 20 mg/kg cadmium addition had a certain inhibitory effect on the root length and root dry matter weight of tobacco, but a certain promoting effect on root volume, and it could first promote and then inhibit the root activity.The combined pollution of metalaxyl with cadmium had a certain inhibitory effect on root length and root dry matter weight, which were reduced by 23.20％ and 31.57％ respectively, compared with those of CK. But the combined pollution had a certain stimulating effect on root volume, and it could first promote and then inhibit the root activity. Moreover, the cadmium addition inhibited the uptake and translocation of metalaxyl by tobacco roots. The response of tobacco root development to the single and combined pollution of metalaxyl and cadmium would provide an important basis for risk assessment of combined pollution of pesticides and heavy metals in tobacco planting soil in the future, and it is also important for composite pollution remediation and improvement.