Bioconcentration and tolerance characteristics of Commelina communis on uranium

In order to study bioconcentration and tolerance characteristics of Commelina communis，and explore its feasibility in phytoremediation of U contaminated soil. A pot experiment was conducted with different concentrations of uranium（U）i.e. 25，75，125，175，275，375 and 485 mg/kg. The U-concentrations in shoots and roots of Commelina communis’s gradually increased with the increase of U-concentration in soil（ 25-375 mg/kg），and the maximum value of 541.73 and 776.497 mg/kg was recorded in soil added with 375 mg/kg. Transfer factor，shoots and roots bioconcentration factor of Commelina communis were in the range of 0.035-0.0698，0.08-1.444，and 1.674-2.56，respectively. The tolerance indexes of maximum quantum yield（ Fv/Fm） among chlorophyll fluorescence parameters，the shoots biomasses，plant heights and root lengths，in different treatments wereanalyzed（ α=0.05）， it was indicated that there were no significant differences between different treatments. The results showed that Commelina communis was a kind of rhizosphere bioconcentration plant，and had a high tolerance to U-concentration with from 25 to 485 mg/kg. As for application of rhizosphere bioconcentration in soil phytoremediation，the essence of phytoremediation is to use plants to gather pollution into the body，then the plants with high concentration of pollution were treated with ash or digestion and so on. Commelina communis’s roots were small in volume and convenient to crop，which had little soil erosion after cropping，when the roots bioconcentration coefficient was greater than 1，its’ roots could be reaped for remediation of heavy metal pollution.