土壤盐分对酶活性和镉形态的影响

为了研究水稻在盐分和镉(Cd)污染作用下的生理变化以及土壤酶活性和镉形态变化,利用盆栽试验在不同盐分处理的重金属Cd污染盐碱土上种植水稻,对酶活性(土壤、植物)及Cd形态转化进行研究。结果表明:在同一Cd污染水平下,盐分从0.3%增加到0.5%时,脲酶和碱性磷酸酶活性提高了2.1%~19.5%和3.8%~64.3%。当盐分含量高于0.5%时,水稻幼苗萎鄢。植物体内过氧化氢酶活性和丙二醛含量随着盐分和Cd含量升高而提高。盐分处理也导致Cd不同形态之间的转换,并改变Cd的形态分布,盐分含量越高交换态和还原态比例升高,说明Cd污染盐碱土上,土壤和水稻酶活性受到多种因素影响。盐分和Cd污染对土壤和植物的影响呈现协同效应。

Effect of Soil Salt on Enzyme Activities and Cd Forms

In order to study the physiological change of rice and soil enzyme activity and cadmium (Cd) forms under cadmium pollution and salt stress, enzyme activities (soil and plant) and soil Cd form transformation were studied by pot experiment under different salt stress. The results showed that the urease and alkaline phosphatase activity increased by 2.1%-19.5% and 3.8%-64.3% when the salt content increased from 0.3% to 0.5% under the same Cd contamination level. When the soil salt content was higher than 0.5% , the rice seedlings withered. The catalase activity and malondialdehyde content increased with the increase of salt and Cd content. The Cd forms and distribution changed with the change of salt content, the ratios of exchange and square Cd increased with the increase of salt content, the exchange forms and reduction forms of Cd increased with higher salt stress. It indicated that the soil and rice enzyme activities were affected by multi-factors in Cd polluted saline-alkali soil. The synergistic effects appeared on soil and rice with salt and Cd contamination.