铜胁迫对白三叶和高羊茅混种富集特性及抗性的影响

Effects of Copper Stress on the Enrichment Characteristics and Resistance of White Clover and Tall Fescue

【目的】研究铜胁迫下白三叶(Trifolium repens)和高羊茅(Festuca elata)混种铜富集特性及抗性变化规律。【方法】采用人工控制性盆栽试验,将白三叶和高羊茅进行1∶1混种,设置0、50、100、150、200、250、300 mg/kg共7种铜胁迫水平,测定2种植物的叶绿素、可溶性糖、可溶性蛋白含量及铜积累量、富集系数、转运系数。【结果】(1)随着铜胁迫浓度增加,2种植物叶绿素含量呈先增后降趋势,可溶性糖和可溶性蛋白含量呈逐渐下降趋势,当铜浓度为250 mg/kg时,2种植物叶绿素和可溶性蛋白含量均受明显抑制;(2)2种植物对铜积累量和富集系数均随铜浓度增加而增加。当铜浓度达到200 mg/kg时,2种植物铜转运系数大于1且均达最大值。【结论】高羊茅和白三叶采用1∶1混种方式,可望在土壤铜浓度<250 mg/kg的污染区作为植物修复应用材料。

【Objective】The aim of this study was to understand the enrichment and resistance of mixed community of white clover(Trifolium repens) and tall fescue(Festuca elata) under copper (Cu) stress.【Method】 A pot experiment was conducted to investigate the chlorophyll,soluble sugar,soluble protein,bioconcentration factors,translocation factors and the copper content of mixed community of white clover and tall fescue (1∶1 planting) under Cu stress. Our experiment included 7 Cu levels (0,50,100,150,200,250, 300 mg/kg).【Result】①The chlorophyll content of the two crops increased first and then decreased with increasing copper stress. However,soluble sugar and protein content of the two crops showed a decreasing trend. When copper concentration was 250 mg/kg,it showed obvious toxic effects on two crops.②The absorption and enrichment coefficients of copper in both aboveground parts and roots of the two crops increased with increasing copper concentration. When copper concentration was 200 mg/kg,the transport coefficients of the two crops was highest(>1).【Conclusion】The mixture (1∶1) of white clover and tall fescue could be used for remediation of contaminated soil where copper content was less than 250 mg/kg.