马蹄金叶片中铜、铅含量及其对生理指标的影响

Cu and Pb contents in Dichondra repens leaf and their effects on its physiological indexes.

研究了草坪草马蹄金对不同污染土壤的Cu、Pb含量 .结果表明 ,马蹄金体内Cu含量 (4 4 8mg·kg-1)高于Pb含量 (2 5 5 9mg·kg-1) 两种元素在体内的分布特征是根、茎 >叶 (P <0 0 5 ) ,并随着土壤内重金属含量增加而增加 ,但富集系数呈下降趋势 ;马蹄金对Cu的富集系数 (0 784 )高于Pb的富集系数(0 4 6 5 ) .自然状态下不同程度Cu、Pb复合污染对马蹄金叶片细胞膜及细胞保护系统的影响结果表明 ,随着Cu、Pb浓度增加 ,叶片内叶绿素a、叶绿素a/b分别由 1 6 10mg·g-1FW和 4 10 0下降到 1 0 17mg·g-1FW和 2 2 99;SOD活性先升高至 10 6 4 94U·g-1FW ,随后下降至 86 2 5 8U·g-1FW ;POD活性则逐渐增加 ;

This paper analyzed the contents of Cu and Pb in Dichondra repens grown on Cu and Pb contaminated soil to determine if this plant is a hyperaccumulator of two elements.The results indicated that total content of Cu (44.8 g·kg -1) in the plant was higher than that of Pb (25.59 g·kg -1),and the contents of two elements were higher in roots and stems than in leaves and increased with increasing soil contamination.The accumulation coefficient of Cu (0.784) was higher than that of Pb (0.465).With the increasing concentrations of two heavy metals,the chlorophyll a content and chlorophyll a/b ratio in leaf decreased,the SOD activity increased to the peak and decreased subsequently,while the POD activity always maintained an increasing trend.The membrane permeability of cell was not significantly varied.