Research on phytoremediation of lead polluted soil by oilseed rape.

Pot experiment was conducted to study the Pb tolerance,uptake and accumulation of oilseed rape under different Pb concentration in soil,and to enhance the remediation effect by adding chelator.The results indicated that low concentration of Pb could increase the plant height,dry weight and chlorophyll contents of oilseed rape to some extent,while high concentration of Pb restrain the growth of oilseed rape.When Pb concentration was 2 000 mg·kg-1,the plant height,dry weight and total chlorophyll content of oilseed rape reduced by 8.0%,21.1% and 51.7% respectively compared with control.The proline content was positively correlated to the Pb concentration(r=0.990 8),reached the highest of 1 227.8 μg·kg-1,was 18 times higher than that of control.Oilseed rape showed certain tolerance to Pb contaminated soil.The accumulation of Pb in roots was much higher than that in shoots and seeds,the Pb contents in different parts of rape and total uptake Pb per pot were significantly increased with the increase of Pb in soil,reached the highest content when Pb concentration was 1 500 mg·kg-1,after that,the Pb content were descent.When Pb concentration were 1 000 mg·kg-1,chelator added to soil significantly increased the Pb concentration of oilseed rape,but with high concentration(15 mmol·kg-1) chelator application,the seedlings died in a few days.The plant with the 10 mmol·kg-1 chelator application had the higher efficiency of Pb phytoextraction.This study implied that 'Qinyou 8' is a promising crop to be used for phytoremediation on Pb contaminated soil.