向日葵对土壤中铜的积累作用研究

温室内不同Cu浓度添加土壤的向日葵盆栽试验表明,向日葵植株的部分生物学性状如地上部干物质量、地下部干物质量、最大单叶面积随土壤中Cu浓度的增加而降低,土壤中添加20mg/kgCu对向日葵根部生长抑制作用最大,而植物高度在添加100mg/kgCu浓度时最高。且不同Cu浓度处理下向日葵对Cu的积累能力不同,但植物各部分Cu含量均随土壤中添加Cu浓度的增加而增加,但在100mg/kgCu浓度处理下,向日葵对Cu的积累主要集中在根部,地上部分Cu含量很低,在200mg/kgCu浓度处理下,向日葵叶中Cu含量超过根部,达857±297mg/kg干重,Cu积累的叶根比达1.27,说明当土壤Cu浓度较高时,Cu在向日葵地上部有较高的Cu积累,集中收获植株地上部分,可移出土壤中的过多有效铜,但生长受到抑制。使用向日葵修复高浓度Cu污染土壤时,还需考虑采用其他手段接种根际微生物、转基因、设施农业环境工程技术等来增加其生物产量。

Accumulating effects of sunflower (Helianthus annuus L.) on copper in soil

Pot experiments cultivating sunflower in different artificially copper-contaminated soil in greenhouse were conducted. The results show that the biological properties of sunflower such as dry weight of shoot, dry weight of root, leaf area are reduced with the increase of copper concentration added to soil. The root growth is seriously inhabited under 200mg/kg Cu treatment. But the maximal plant height is gotten under the 100mg/kg Cu treatment. It is also found that the accumulating ability of copper of sunflower changes with the copper concentration. The root of sunflower accumulates more copper when the Cu concentration in soil is lower, while the Cu contents in shoot are very low. Under the treatment of 100mg/kg Cu in soil, the Cu content in the leaves is higher than that in the root, reaching 857±297mg/kg (dry weight), and the ratio of Cu accumulation in leaf to that in root reaches 1.27. So the sunflower can extract more copper by the harvesting because there is a higher accumulation of Cu in the sunflower shoots and leaves when Cu concentration in the soil is higher, but the growth of sunflower is restrained. So when sunflower is used to remediate copper-contaminated soil, other means such as inoculation of rhizospheric microorganisms, transgenic, agro-biological environmental engineering technique, and so on should be considered to increase its biomass.