银中杨各部位对Cd、Zn、Pb的富集特性

姜礅; 王月月; 严善春

doi:10.13332/j.1000-1522.20170191

摘要:

目的为探明银中杨各部位对不同重金属的富集特性。

方法本研究通过用3种不同含量的镉(Cd，0.5、1.5、2.5 mg/kg)、锌(Zn，300、500、700 mg/kg)或铅(Pb，300、500、700 mg/kg)分别处理盆栽一年生银中杨的土壤，分析银中杨根、茎、叶对Cd、Zn和Pb的富集量和富集系数。

结果银中杨根、茎、叶对Cd、Zn和Pb的富集量均与土壤中相应的重金属含量呈极显著的正相关(P < 0.01)。高含量Cd处理下的根、茎、叶对Cd的富集系数均不同程度的低于低含量处理；高含量Zn处理下叶对Zn的富集系数和高含量Pb处理下叶对Pb的富集系数也均不同程度的低于低含量处理，但根、茎对Zn的富集系数对Zn的处理含量不敏感，而根、茎对Pb的富集系数却对Pb的处理含量呈依赖性。银中杨各部位之间对Cd的富集量未表现出任何规律，但对Cd的富集系数，在低含量下一致，在高含量下根显著低于茎和叶(P < 0.05)。Zn低含量处理下的叶、根、茎和高含量处理下的根、叶、茎对Zn的富集量和富集系数均依次有不同程度的降低。Pb各含量处理均使根对Pb的富集量和富集系数显著高于茎和叶(P < 0.05)。

结论说明土壤中的Cd、Zn和Pb含量影响银中杨对其的富集，且呈根茎叶特异性。银中杨各部位对Cd的富集情况表现为茎和叶的富集阈限高于根部；对Zn的富集情况在低含量时表现为叶>根>茎，在中、高含量时表现为根>叶>茎；对Pb的富集主要集中在根。

Abstract:

ObjectiveThis study aims to investigate the accumulation characteristics of different heavy metals in all parts of Populus alba 'Berolinensis'.

MethodWe analyzed the bio-accumulation amount and bio-concentration factor (BCF) of roots, stems and leaves to cadmium (Cd), zinc (Zn) and lead (Pb) after treating the soil with three concentrations of each heavy metal. For Cd, we used 0.5, 1.5 and 2.5 mg/kg; for Zn we used 300, 500 and 700 mg/kg; and for Pb, the concentrations were 300, 500 and 700 mg/kg.

ResultOur results showed that the bio-accumulation amounts of Cd, Zn and Pb in roots, stems and leaves were all significantly positively correlated with corresponding heavy metal content in the soil (P < 0.01). High concentration treatment of Cd resulted in the BCF of all the plant parts in response to Cd to be lower than those for low treatment concentrations; The BCF of leaves to Zn in high concentration treatment of Zn and the BCF of leaves to Pb in high concentration treatment of Pb were lower than those in low treatment concentrations. The BCF for roots and stems of Zn was not sensitive to the Zn treatment concentrations, whereas the BCF of roots and stems to Pb was dependent on Pb treatment concentrations. The bio-accumulation amount of Cd in all plant parts did not show any clear trends. The BCF of Cd among all parts showed no differences in response to the lowest concentration, but the BCF of the roots was significantly lower than those of the stems and leaves under the highest concentration (P < 0.05). The bio-accumulation amount and BCF of leaves, roots, stems for Zn in the low concentration treatment group, and of roots, leaves, stems in the high concentrations treatment groups decreased in turn. The bio-accumulation amounts and BCF of Pb in roots for all Pb concentrations applied were higher than those of the stems and leaves (P < 0.05).

ConclusionThe above results indicated that the concentrations of Cd, Zn and Pb in soil caused different, specific accumulations of these three heavy metals in Populus alba 'Berolinensis' roots, stems, and leaves. With regard to accumulation in all three parts of the Populus alba 'Berolinensis' plants, for Cd the enrichment thresholds of stems and leaves were higher than those of roots. For Zn, the accumulation results showed a trend of leaf > stem > root at low treatment concentrations and a different trend of root > leaf > stem at moderate and high treatment concentrations. For Pb, the accumulation was always greatest in the roots.

银中杨各部位对Cd、Zn、Pb的富集特性

Accumulation characteristics in all parts of Populus alba 'Berolinensis' to cadmium, zinc, and lead