锌铬复合污染对水稻根系抗氧化酶活性的影响

为了研究水稻在金属复合污染条件下的适应过程,该文就成都平原两种常见的重金属污染元素(锌、铬)对土壤复合处理后,进行水稻盆栽试验.结果表明,锌铬复合污染条件下,在水稻不同生育期,水稻根系3种抗氧化酶(SOD,POD和CAT)活性随锌、铬浓度的增加而表现出不同的变化趋势.在水稻分蘖期,随铬浓度的增加,水稻根系SOD活性和POD活性呈先降后升的变化趋势;随锌浓度的增加,水稻根系SOD活性和POD活性呈升高的趋势;而水稻根系CAT活性则随锌、铬浓度的增加呈一定的降低趋势.在水稻孕穗期,随锌、铬浓度的增加,水稻根系SOD活性呈先降后升的变化趋势,POD活性及CAT活性则呈降低的趋势.在水稻灌浆结实期,水稻根系SOD、POD及CAT活性均呈一定的降低趋势.水稻籽粒产量随锌、铬浓度的增加呈降低的趋势.锌、铬浓度对水稻籽粒产量产生了复合效应,并与水稻籽粒产量有极显著的线性回归关系.这表明水稻通过调节自身的生理代谢能提高对锌铬复合污染的生态适应性,这能为培育适合重金属污染地区生长的水稻品种提供理论基础.

Effects of compound pollution of Zn and Cr on antioxidant enzyme activity of rice (Oryza sativa L.) roots

In order to study the adaptation processes of rice plants under compound pollution of heavy metals, two heavy metals (Zn and Cr) which are common pollution elements in Chengdu Plain were added in the soil, and planted rice plants in the pots in this experiment. The results showed that three antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT)) activities of rice roots were showen in different trends at different growth stages of rice plants with increasing concentration of Zn or Cr. At tillering stage of rice plants, SOD and POD activities of rice roots had a trend of reducing first and increasing afterwards with increasing concentration of Cr, and had an increasing trend with increasing concentration of Zn, and CAT activity of rice roots had a reducing trend with increasing concentrations of Zn and Cr. At booting stage of rice plants, SOD activity of rice roots had a trend of reducing first and increasing afterwards with increasing concentrations of Zn and Cr, but POD and CAT activities of rice roots had a reducing trend. At filling stage of rice plants, SOD, POD and CAT activities of rice roots had a trend of reducing with increasing concentrations of Zn and Cr. Grain yield of rice plants had a reducing trend with increasing concentrations of Zn and Cr. The concentrations of Zn and Cr had compound pollution effects on grain yield of rice plants, and had highly significant linear regression with it. These indicated that rice plants could adjust its physiological metabolism to improve the ecological adaptability to compound pollution of Zn and Cr, and it provides theoretical basis for cultivating rice varieties which can grow in heavy metal contaminated areas well.