State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, China.
Environ Toxicol Chem. 2014 Mar;33(3):671-6. doi: 10.1002/etc.2489. Epub 2014 Jan 24.
The present study aimed to determine the toxic effects of chromium (Cr) on cabbage (Brassica oleracea), cucumber (Cucumis sativus), lettuce (Lactuca sativa), wheat (Triticum aestivum), and corn (Zea mays), and identify the sensitive plant species and appropriate bioassays for potential use in phytotoxicity assessment of Cr in soil. Results showed that seed germination might not be a sensitive assay for assessing Cr toxicity because at most of the Cr levels there were no toxic effects. Root elongation was more sensitive to Cr than seed germination. The lowest concentration of adverse effect (LOAEC) of lettuce was 20 mg Cr/kg(-1) soil, and that of the other 4 species was 50 mg Cr/kg(-1) soil. The mitotic index fluctuated with increasing Cr concentration, thus it was insufficient to assess toxicity of Cr in soil. However, micronucleus assay showed that 5 mg Cr/kg(-1) soil caused a significant increase in micronucleus frequency in cabbage, cucumber, and lettuce. For wheat and corn, however, the LOAEC was 20 and 50 mg/Cr/kg(-1) soil, respectively. Furthermore, the analysis of Cr accumulation showed that lettuce significantly accumulated Cr for all the tested concentrations. However, corn and wheat significantly accumulated Cr only with the highest tested dose. This may explain the higher inhibitory effects of Cr on root growth. It can be concluded that root elongation and micronucleus assay are good indicators to assess the phytotoxicity of Cr in soil. Lettuce is the most sensitive species for indicating the toxicity of Cr in soil.
本研究旨在确定铬（Cr）对甘蓝（Brassica oleracea）、黄瓜（Cucumis sativus）、生菜（Lactuca sativa）、小麦（Triticum aestivum）和玉米（Zea mays）的毒性影响，并确定敏感植物物种和适当的生物测定方法，以用于评估土壤中 Cr 的植物毒性。结果表明，种子萌发可能不是评估 Cr 毒性的敏感测定方法，因为在大多数 Cr 水平下没有毒性作用。根伸长比种子萌发对 Cr 更敏感。生菜的最低不良效应浓度（LOAEC）为 20mgCr/kg（-1）土壤，而其他 4 种植物的 LOAEC 为 50mgCr/kg（-1）土壤。有丝分裂指数随 Cr 浓度的增加而波动，因此不足以评估土壤中 Cr 的毒性。然而，微核试验表明，5mgCr/kg（-1）土壤会导致甘蓝、黄瓜和生菜的微核频率显著增加。然而，对于小麦和玉米，LOAEC 分别为 20 和 50mgCr/kg（-1）土壤。此外，Cr 积累分析表明，生菜对所有测试浓度均显著积累 Cr。然而，玉米和小麦仅在最高测试剂量下才显著积累 Cr。这可能解释了 Cr 对根生长抑制作用较高的原因。可以得出结论，根伸长和微核试验是评估土壤中 Cr 植物毒性的良好指标。生菜是指示土壤中 Cr 毒性的最敏感物种。
