Variation of Cadmium Tolerance and Accumulation in Different Tobacco Cultivars

Pot experiments were carried out to study the variation of cadmium tolerance and accumulation in 16 tobacco cultivars.The results showed that at higher soil cadmium level,the cultivar Xanthi had higher biomass of root and shoot,indicating its tolerance to cadmium,Gui Yan 11 had lower biomass of root and shoot,indicating its weak tolerance to cadmium,and the other cultivars with less biomass change were moderately tolerant to cadmium. Tobacco appeared to have high ability to absorb cadmium.The accumulation of cadmium in the shoot of tobacco was much higher than that in the root.Furthermore,68%~88% of cadmium was found to distribute in the leaves of tobacco,implying its high translocation rate of cadmium from the root to the leaf.The content of cadmium in the leaf of tobacco was higher than that in the stem and root.However significant differences were observed between different tobacco cultivars in cadmium content in their root,stem and leaves.The cadmium contents in the leaves of Guiyan11,RG17,Yunyan 87,CF965 and NC82,were above 100 mg/kg at 10 mg/kg of soil cadmium,which is characteristic of cadmium hyper-accumulators.Due to the high biomass,high ability to accumulate cadmium and easiness for harvesting,tobacco has a great potential for application in phyto-remediation of cadmium polluted soils.