title: Seed germination, root elongation, root-tip mitosis, and micronucleus induction of five crop plants exposed to chromium in fluvo-aquic soil.
abstract: 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.
authors: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, China.
authors: Jing-
authors: J
authors: Hou
authors: Guan-Nan
authors: GN
authors: Liu
authors: Wei
authors: W
authors: Xue
authors: Wen-Jun
authors: WJ
authors: Fu
authors: Bao-Cui
authors: BC
authors: Liang
authors: Xin-Hui
authors: XH
authors: Liu
mesh_terms: D001937:Brassica / Q000187:drug effects / Q000254:growth & development; D002857:Chromium / Q000633:toxicity*; D018556:Crops, Agricultural / Q000187:drug effects* / Q000254:growth & development; D018553:Cucumis sativus / Q000187:drug effects / Q000254:growth & development; D018545:Lactuca / Q000187:drug effects / Q000254:growth & development; D018519:Meristem / Q000187:drug effects / Q000254:growth & development; D015162:Micronucleus Tests; D008938:Mitosis / Q000187:drug effects*; D018517:Plant Roots / Q000187:drug effects* / Q000254:growth & development; D012639:Seeds / Q000187:drug effects* / Q000254:growth & development; D012987:Soil; D012989:Soil Pollutants / Q000633:toxicity*; D014908:Triticum / Q000187:drug effects / Q000254:growth & development; D003313:Zea mays / Q000187:drug effects / Q000254:growth & development
chemical_list: D012987:Soil; D012989:Soil Pollutants; D002857:Chromium
keywords: Bioassays; Chromium; Genotoxicity; Indicator; Phytotoxicity