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 stemleaf.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.