Xu Wei-hong, Wang Hong-xin, Liu Huai, Xiong Zhi-ting, Singh Balwant
College of Resources and Environmental Sciences, Southwest University, Chongqing 400716, China.
Huan Jing Ke Xue. 2007 Sep;28(9):2089-95.
Pot experiments (root rag method) were carried out to investigate the influence of individual and combined pollution of cadmium (Cd) and zinc (Zn) on plant growth, Zn and Cd accumulation in ryegrass (Loliurn perenne L.), rhizosphere Zn and Cd fractions. The results showed that the synergistic effect on uptake between Zn and Cd was observed in the Zn and Cd existing concurrently treatment (8 mmol/kg Zn and 2 mmol/kg Cd) while Zn uptake by ryegrass deceased in the Cd alone treatment (2 mmol/kg Cd). Zn and Cd were distributed mainly in shoot. The highest Zn and Cd concentrations (3 108.72, 73.97 mg/kg, respectively) were found with the combined Zn and Cd treatment and this trait could be beneficial in the selection of high Zn accumulator for soil Zn phytoremediation. The results show that ryegrass has a high potential for soil Zn phytoremediation. The concentrations of Zn fractions (EXC, CAB and FeMn) in rhizosphere were higher than that of bulk soil. Rhizosphere and bulk soil Cd fractions were in the order of EXC > CAB > FeMn > RES > OM in Cd alone and Cd and Zn combined treatments. Rhizosphere and bulk soil Zn fractions were in the order of FeMn > CAB > RES > OM > EXC in Zn alone and Cd and Zn combined treatments, while the order was RES > FeMn > OM > CAB > EXC in Cd only treatment. The concentrations of amino acids increased and soil rhizosphere pH decreased with alone Cd, Zn and combined Cd and Zn treatments. The maximum amino acids concentration was found in the combined Cd-Zn treatment which was approximately 1.95, 1.54 and 1.40 times compared to concentration in the control, Zn and Cd individual treatments, respectively. The minimum of soil pH (5.18) in rhizosphere was found in the combined Cd and Zn treatment.
通过盆栽试验（根袋法）研究了镉（Cd）和锌（Zn）单一及复合污染对植物生长、黑麦草（Lolium perenne L.）中锌和镉积累、根际锌和镉形态的影响。结果表明，在锌和镉共存处理（8 mmol/kg锌和2 mmol/kg镉）中观察到锌和镉对吸收的协同效应，而在单一镉处理（2 mmol/kg镉）中黑麦草对锌的吸收减少。锌和镉主要分布在地上部分。锌和镉复合处理下锌和镉的浓度最高（分别为3108.72、73.97 mg/kg），这一特性可能有利于筛选用于土壤锌植物修复的高锌积累植物。结果表明黑麦草在土壤锌植物修复方面具有很大潜力。根际中锌形态（交换态、碳酸盐结合态和铁锰氧化物结合态）的浓度高于非根际土壤。在单一镉处理以及镉和锌复合处理中，根际和非根际土壤镉形态的顺序为交换态＞碳酸盐结合态＞铁锰氧化物结合态＞残渣态＞有机结合态。在单一锌处理以及镉和锌复合处理中，根际和非根际土壤锌形态的顺序为铁锰氧化物结合态＞碳酸盐结合态＞残渣态＞有机结合态＞交换态，而在单一镉处理中顺序为残渣态＞铁锰氧化物结合态＞有机结合态＞碳酸盐结合态＞交换态。单一镉、锌以及镉和锌复合处理均使氨基酸浓度增加，土壤根际pH值降低。镉锌复合处理中氨基酸浓度最高，分别约为对照、单一锌处理和单一镉处理浓度的1.95、1.54和1.40倍。根际土壤pH值最低（5.18）出现在镉和锌复合处理中。
