重金属Pb、Cr、Cd对烟草生长的影响及其分布规律

[目的]研究重金属Pb、Cr、Cd对烟草的生理作用及其在烟草中的吸收累积规律.[方法]采用盆栽试验方法,测定烟草根、茎、叶等器官中Pb、Cr、Cd含量,分析不同重金属污染程度下烟草的株高及叶片干物质重的变化.[结果]重金属处理的土壤中烟草的株高都显著低于对照,呈现抑制作用,添加外源Pb和Cr处理下,烟草叶片干重随添加浓度的升高而降低,Cd处理则呈现出先升高后降低的趋势.Pb、Cr、Cd重金属在烟草器官中的含量均为根>茎>叶,根系中Pb、Cr、Cd的浓度与添加浓度具有较好的相关性,而叶片中只有Cd含量与添加浓度具有较好的相关性.[结论]烟草植株中的重金属主要来源于土壤,烟草对重金属的传输过程具有一定的滞阻作用.

Physiological action,growth,and accumulation rules of Pb,Cr,and Cd in tobacco

【Objective】The physiological action and accumulation of Pb， Cr， and Cd in tobacco were estimated and studied in this research. 【Method】Using pot experiments，the concentration of Pb， Cr， and Cd in root，stem， and leaf of tobacco were measured； the plant height and leaf dry matter weight under different metal contamination degree were also determined. 【Result】The plant height measured from tobacco sampled from heavy metal soil was significantly lower than that measured from the control group. With inhabitation and the addition of exogenous Pb and Cr treatment， the tobacco leaf dry weight exhibited negative correlation with additive concentrations. The Cd treatment initially increased then decreased. The heavy metals concentration in tobacco tissues increased in the following order: root＞stem＞leaf. In tobacco roots， the Pb， Cr， and Cd concentration showed good correlation with the addition of exogenous Pb Cr， and Cd， while in tobacco leaves， only the Cd concentration showed good relativity. 【Conclusion】The heavy metals in tobacco plants mainly originated from soil； however， the heavy metal transfer process demonstrated blocking effect， which limited the metal transfer content.