CaCO_3对黄豆生长过程中Cd毒害的缓解效应

Mitigative Effects of CaCO_3 to Growth of Clycine max in Cd-Polluted Soils

采用盆栽试验方法,研究了Cd污染土壤中施用CaCO3对黄豆生物量、叶绿素含量、叶片SOD活性和MDA含量的影响,即CaCO3对黄豆生长过程中Cd毒害的缓解效应.结果表明,在Cd污染土壤中,适量施用CaCO3可以显著增加黄豆植株高度、生物量、叶绿素含量和叶片SOD活性,降低叶片MDA含量,说明CaCO3能有效缓解Cd对黄豆的毒害.以黄豆豆荚鲜重为指标,在本试验条件下,未受Cd污染的土壤中,CaCO3的建议施用量为0.5 g/kg;Cd污染水平为5 mg/kg的土壤中,CaCO3的建议施用量为2 g/kg.

A pot experiment was conducted to study mitigative effects of CaCO3 to growth of Clycine max plants in the soils polluted with Cd through measuring the biomasses,chlorophyll contents,leaf superoxide dismutase (SOD) activities and malondialdehyde (MDA) contents of the plants.The results showed that proper application of CaCO3 significantly increased the heights,biomasses,chlorophyll contents,and leaf SOD activities,and decreased leaf MDA contents in Clycine max plants in the tested Cd-polluted soils,indicating that suitable application of CaCO3 could effectively mitigate toxicity of soil Cd to Clycine max plants. If the fresh weight of bean-pod was used as the index to evaluate the mitigative effect of CaCO3 application in this experiment,0.5 g/kg was the best application amount of CaCO3 to the unpolluted soil,while 2 g/kg was the best application amount to the soil polluted with Cd at 5 mg/kg.