中文摘要：

通过小麦的盆栽实验研究了生物可降解有机配体EDDS、柠檬酸和半胱氨酸在5mmol·kg^-1浓度下对土壤中重金属Cu、Cd、Pb和Zn的植物富集的影响，同时采用0．1mol·L^-1 HAc提取元素可交换态含量与植物实验相对照。结果发现，在所试验的外源土壤金属浓度下．EDDS处理对所研究的金属在小麦幼苗体内的富集和它们在小麦幼苗体内的传输有明显的诱导作用。EDDS处理组的小麦根和茎叶金属含量均高于对照组。EDDS处理组Cd、Cu、Zn和Pb的茎叶富集系数（分别为0．209、0．640、0．339和0．726）远高于对照组Cd、Cu、Zn和Pb的茎叶富集系数（分别为0．059、0．071、0．046和0．353）。柠檬酸处理和半胱氨酸处理对Cu、Zn和Pb的茎叶富集系数影响不大，但明显提高了Cd的茎叶富集系数（分别为0．118和0．115）。添加EDDS后土壤中4种重金属的可交换态含量增加最明显。半胱氨酸对可交换态含量影响不明显，这与小麦体内富集的金属含量趋势相一致。对于不同的金属而言，Cd的根系相对富集量比较高．可达外源添加浓度的2．46倍（EDDS处理组），其可交换态的相对含量也最高，可达外源添加浓度的68．6％-96．9％。Pb的植物富集效率和可交换态含量较低。

英文摘要：

The effects of biodegradable organic ligands such as [s,s＇]-ethylenediamine disuccinic acid （EDDS）, citric acids and cysteine on the phyto-concentration of four heavy metals （Cu, Cd, Pb, Zn） in sandy soil were investigated using pet experiment of wheat seedlings. 5 mmol ·kg^-1 EDDS, citric acids and cysteine were added respectively. The phytoextraction of the four metals were also assessed by their fractions extracted by 0.1 mol· L^-1 HAc. The results showed that the addition of 5 mmol· kg^-1 EDDS greatly induced the concentration and transposition of the investigated metals in wheat seedlings. Shoot concentration factors of the seedlings treated by EDDS （0.209, 0.640, 0.339 and 0.726 respectively） were greatly higher than that of the control （0.059, 0.071, 0.046 and 0.353 respectively）. Citric acids and cysteine only had slight effects on the shoot concentration factors of Cu, Zn and Pb, but greatly improved that of Cd （0.118 and 0.115 respectively）, The fractions of the four metals extracted by 0.1 mol· L^-1 HAc in the soils after cultivation increased significantly under the treatment of EDDS, but the addition of cysteine had little effects. The performance was corresponding with the results gained in pot experiment. Among the four metals, the root concentration of Cd was the highest, 2.46 times of the spiked concentration in the treatment of EDDS. The fraction of Cd extracted by 0.1 mol ·L^-1 HAc was also the highest, 68.6%-96.9% of the spiked concentration in the soils. The lowest uptake and fraction extracted by 0.1 mol· L^-1 HAc were found in all treatments with lead except shoot concentration in EDDS treatment.