Cd、Pb 单一及复合污染对广西莪术生长的影响及其富集特性研究
Curcuma kwangsiensis S.G. Lee et C.F. Liang’s growth and accumulation under single and combined pollution of Cd and Pb
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摘要: 以盆栽广西莪术为试验材料,用不同浓度的 Cd、Pb 单一及其复合处理,研究植物的生长变化及其体内 Cd、Pb 的积累和迁移。结果表明,Cd 1 mg/kg、Pb 100 mg/kg 处理,广西莪术并没有出现毒害现象;其他处理表现出明显的毒害现象,且浓度越高,植株受到的伤害越大。叶绿素含量均随重金属浓度增大而下降,仅在处理30 d 低浓度时,叶绿素含量显著上升。叶绿素a/b 随污染浓度的增加而降低,而且单一重金属胁迫对植物叶绿素含量的影响小于复合重金属胁迫。广西莪术对Cd、Pb 具有富集作用,地上部和地下部Cd 、Pb 含量均随着处理浓度升高而显著增加,且复合污染比单一污染的含量高。各处理广西莪术药用部位的Cd 、Pb 均未达到《药用植物及制剂外经贸绿色行业标准》 ( WM/T2—2004)标准,其中对照地下部Cd含量超过标准的7.43 倍,Pb 含量超过标准的7.58 倍,在栽培生产过程中须严格监控土壤中Cd、Pb 两种重金属的含量,以免抑制植株生长和重金属含量超标。Abstract: Using the method of pot culture,Curcuma kwangsiensis S.G. Lee et C.F. Liang was treated by single and combined concentrations of Cd and Pb. The growth changes as well as accumulation and transference of Cd and Pb were studied. The results showed that with the increase of concentration of Cd and Pb respectively,the aboveground and underground dry weight of C. kwangsiensis S. G. Lee et C. F. Liang all decreased,except 1 mg/kg of Cd and 100 mg/kg of Pb. With the increase of concentration of Cd and Pb respectively,the chlorophyll decreased, except 1 mg/kg of Cd and 100 mg/kg of Pb at 30 days. The chlorophyll a/b decreased as concentration of Cd and Pb increasing,but the chlorophyll a/b of combined treatments were lower than that of single treatments. The contents of Cd and Pb in aboveground and underground went up with the increase of concentrations of heavy metals in all treatments,and the accumulated amount in underground was higher than that in aboveground. Under combined treatments,the contents of Cd and Pb in different organs of C. kwangsiensis S. G. Lee et C. F. Liang were more than that under single treatments,and the contents of Cd and Pb in medicinal part of C. kwangsiensis S. G. Lee et C. F. Liang of all treatments exceeded the standard of
(WM/T2—2004),the contents of Cd and Pb in medicinal part of C. kwangsiensis S. G. Lee et C. F. Liang of control were 7.43 and 7.58 times of the standard,respectively. The results indicated that C. kwangsiensis S. G. Lee et C. F. Liang was a potential phytoremediation plant for a low concentration of combined heavy metal polluted soil,it was necessary to strictly monitor the contents of Cd and Pb in the soil in the process of cultivation,so as to avoid exceeding the standard.