DOI: 10.3724/SP.J.1258.2013.00115

Chinese Journal of Plant Ecology (植物生态学报) 2013/37:12 PP.1123-1131

Growth effects and accumulations of polycyclic aromatic hydrocarbons (PAHs) in rape

Aims Polycyclic aromatic hydrocarbons (PAHs) are a large class of ubiquitously occurring persistent organic pollutants (POP). Plants can take up PAHs through atmospheric sedimentation and sewage irrigation, resulting in serious hazards on the food safety and human’s health. Our objective was to investigate the effects of fluoranthene (FLU) and benzo-a-pyrene (B[a]P) on growth, physiological performance, and quality of rape (Brassica chinen-sis), and to understand their patterns of accumulations in stem and leaves. Methods Rape seedlings were transplanted to grow in soils with different rates of FLU and B[a]P addition, i.e. 0, 0.5, 1.0, 5.0, and 10.0 mg·kg–1, respectively. Growth indicators including leaf length, leaf width, plant height and aboveground biomass, and physiological properties including photosynthetic rate (Pn), chlorophyll content, and the content of vitamin C were measured to determine the effects of the two PAHs on rape. Accumulations of FLU and B[a]P were measured by the method of high performance liquid chromatography (HPLC). Pearson cor-relation analysis was performed to investigate the relationships between the accumulations of the PAHs and vari-ous growth indicators. Important findings We found that the accumulated concentrations of FLU and B[a]P in rapes increased with the level of FLU and B[a]P in soils. The accumulations of FLU in stems and leaves differed significantly (p < 0.05) among treatments with different rates of FLU addition. As compared with the control (CK), the accumulations of B[a]P in rapes significantly increased in treatments with 5.0 and 10.0 mg·kg–1 B[a]P addition, and the highest amount of accumulation at 10 mg·kg–1 was below the national food security standard. Low concentrations of FLU and B[a]P had positive effects on leaf length, leaf width and the aboveground biomass; whereas high concentra-tions had negative impacts. As compared with CK, plant height and Pn significantly decreased with of the level of FLU and B[a]P treatments. Chlorophyll content increased at lower concentrations but declined at higher concen-trations. Overall, the reduced vitamin C was inhibited by FLU; it was lowest at 5.0 mg·kg–1 of FLU. The reduced vitamin C varied irregularly with B[a]P treatments; it increased slightly at 0.5 mg·kg–1 of B[a]P and was lowest at 5.0 mg·kg–1 of B[a]P, compared with CK.

Key words:accumulation characteristics, benzo-a-pyrene (B[a]P), Brassica chinensis, fluoranthene (FLU), physiological response, reduced vitamin C

ReleaseDate:2014-07-21 17:02:02