| 摘要: |
| 【目的】研究铜(Cu)和铬(Cr(Ⅵ))单一及复合污染对小白菜种子萌发和根长的生态毒性，为铜、铬复合污染的预测、评价和修复提供依据。【方法】以小白菜“秦白2号”种子为试材，采用培养试验方法，研究铜、铬单一及复合污染对种子发芽率、发芽势、发芽指数及根长的影响。【结果】低含量铜、铬对小白菜种子发芽指标影响不显著，而高含量铜(≥800 mg/kg)、铬(≥60 mg/kg)对小白菜种子萌发产生显著抑制作用(P<0.05)。外源铬含量与小白菜根长抑制率呈极显著线性关系(P<0.01)；低含量铜(≤200 mg/kg)可促进根伸长，而高含量铜对根长产生明显的抑制作用。铜和铬复合污染对小白菜种子发芽及根长抑制率均表现为拮抗毒性，铜对铬毒性效应拮抗作用的大小与铜含量有关。【结论】铜、铬复合污染对小白菜种子的萌发影响不大，但对根长影响明显，建议以种子的根长抑制率作为判断铜、铬最初生物毒性的指标。 |
| 关键词: 重金属污染 复合污染 种子萌发 根长抑制率 小白菜 |
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| 基金项目:国家科技支撑计划项目（2008BADA4B09） |
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| Single and combined toxicity of chromium and copper to seed germination and root elongation of Pakchoi(Brasica chinensis) in soils |
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| Abstract: |
| 【Objective】The elements Cu and Cr are two important heavy metal pollutants.In this study the single and combined effects of Cu and Cr(Ⅵ) on the seed germination and the root elongation of Pakchoi (Brassica chinensis) were investigated in order to provide scientific basis for the predication,evaluation and repair of copper and chromium combined pollution.【Method】With the seeds of pakchoil “Qinbai 2” as material,the soil culture experiments were conducted to study the effects of single and combined pollution of copper and chromium on seeds germination energy,germination rate and root inhibition ratio.【Result】The results showed that seed germination indexes were not significantly affected in low concentrations of Cu and Cr treatments,whereas the root enlogation inhibition rate was remarkable in high concentrations of Cu (≥800 mg/kg) and Cr(≥60 mg/kg) treatments (P<0.05).It was found that there were significant liner relationships between concentration of Cr (Ⅵ) and root elongation (P<0.01) and low concentration of Cu (≤200 mg/kg) could accelerate the root elongation while high concentration of Cu could inhibit it significantly.Cu and Cr had antagonistic effects on seeds germination and root elongation of Pakchoi Meanwhile,the antagonism of Cu against Cr was in response to the concentration of Cu.【Conclusion】In conclusion,the toxicity of the pollutants to seed germination is lower than to root elongation.It’s suggested that the seed root length inhibition rate be taken as indicator to determine heavy metal biological toxicity |
| Key words: heavy metals pollution combined pollution seed germination inhibition rate of root elongation pakchoi |
