烟草对复合污染土壤中镉的吸收运转及改良的研究

目的]研究烟草对重金属镉的吸收运转规律,改良剂对重金属的改良效果,为最终实现人工调控镉活性提供科学依据。方法]采用盆栽试验,研究了在复合污染的土壤中烟草对重金属镉的吸收规律,5种改良剂对重金属的改良效果以及烟草体内镉与鲜重和其他重金属的相互关系。结果]烟草对镉的转移系数在2.28～4.60,向上迁移镉元素能力强。烟草属于镉元素耐性作物,随生育期推移不同部位的镉含量呈下降趋势。加入修复剂在不同程度上减少了烟株体内的镉含量。不同部位的镉含量与其鲜重呈显著负相关。在复合污染的条件下,烟株体内镉的含量与其他重金属(Pb、As和Hg)存在着显著正相关关系。结论]修复剂在减少烟草镉含量的同时也降低了其他重金属的含量,提高了烟草的生物学产量,达到了提高烟草安全品质和产量的双重功效。

Study on the Absorption and Translocation of Cadmium in Tobacco in Compound Pollution Soil and the Improvement Effect on Cadmium Pollution by Remediators

Objective] The research aimed to study the absorption and translocation law of heavy metal cadmium(Cd) in tobacco and the improvement effects of remediators on heavy metals, and provide scientific basis for realizing the artificial regulation of Cd activity eventually. Method] In pot test, the absorption law of tobacco in the soil with compound pollution to heavy metal Cd, the improvement effects of 5 kinds of remediators on heavy metals and the interrelationships between Cd in tobacco and fresh weight, other heavy metals were studied. Result] The transfer coefficient of Cd in tobacco ranged from 2.28 to 4.60 and the ability of translocating Cd element from roots to leaves was strong. Tobacco belonged to crops with tolerance to Cd element and Cd content in different parts showed a decreasing trend along with the process of growth stage. Adding remediators decreased Cd content in tobacco plant to different degree. Cd content in different parts showed a significantly negative correlation with its fresh weight. Under the conditions of compound pollution, Cd content in tobacco plant had significant positive correlation with other heavy metals (Pb, As and Hg). Conclusion] Remediators decreased Cd content in tobacco, at the same time they also decreased the contents of other heavy metals, which increased the biomass yield of tobacco and reached the double efficacy of increasing the safety quality and yield of tobacco.