Tang XinyunSun Yiyang, Wen Chongqing, Gan Xuhua, Zhang Zili(Life Science College, Anhui Agricultural University, Hefei 230036, China)
Rare earth elements(REE)are applied as micro-fertilizer in large scale in China and there is growing concern about the environmental effects of REE accumulation in soils. Accumulation of REE was simulated in lab by adding REE to three soils and the survival of Pseudomonas fluorescence X16 strain marked with luxAB gene in soils was detected. Curvilinear regression method was applied to analyze the survival pattern. The stimulation values, EC_(50) and NOEC values for X16 strain were calculated to compare the toxic intensity of REE in different soils. The stimulation(peak)values in red soil, yellow fluovo-aquic soil and yellow cinnamon soil, are 11.55～18.08,(0～2.13), 2.37～4.62 mg·kg~(-1) , respectively. EC_(50) values are 13.47～39.12, 6.59～56.18, 372～1034 (mg·kg~(-1)), respectively.NOEC values are 5.62 ～21.41, 0.00～4.53, 133.3～327.1 mg·kg~(-1), respectively. Tangents values of regression equation of the survival of X16 strain in red soil are the maximum ones indicating that REE accumulation in red soil has stronger inhibitory effects than in other two soils. The soil order, reflecting toxic intensity of REE is as follows: red soil>yellow fluovic-aquic soil>yellow cinnamon soil.
Pedotogy; simulated accumulation; Pseudomonas fluorescence; lux gene marker; ecotoxicity evaluation;rare earths
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