牛繁缕对镉的积累特性研究  

Cadmium Accumulation Characteristics of Malachium Aquaticum

作　　者：张潇[1] 林立金[2] 廖明安[1] 杨代宇 何静[1] 马倩倩[1] 刘春阳[1] 袁雷[1] 

机构地区：[1]四川农业大学园艺学院,四川成都611130 [2]四川农业大学果蔬研究所,四川成都611130

出　　处：《土壤通报》2015年第3期615-620,共6页Chinese Journal of Soil Science

基　　金：国家农业科技成果转化资金项目(2011GB2F000006)资助

摘　　要：以牛繁缕为试材,采用盆栽试验研究其在不同镉浓度条件下的镉积累特性。结果表明:牛繁缕根系生物量、地上土壤部分生物量和总生物量均随土壤镉浓度的升高而降低。在土壤镉浓度小于100 mg kg-1时,牛繁缕的抗性系数均大于0.5;当土壤镉浓度为25 mg kg-1时,抗性系数最大,为0.931。在不同镉浓度条件下,牛繁缕光合色素的合成会受到一定程度的抑制,叶绿素b、类胡萝卜素和叶绿素总量均随镉污染浓度的增加而逐渐降低,但叶绿素a和a/b值则表现为波动变化的趋势。随土壤镉浓度的增加,牛繁缕根系及地上部分镉含量呈增加的趋势;当土壤镉浓度为100 mg kg-1时,牛繁缕地上部分镉含量为118.94 mg kg-1,大于镉超富集植物临界值(100 mg kg-1)。牛繁缕根系和地上部分富集系数均大于1,但转运系数小于1。牛繁缕根系、地上部分和整株的镉积累量最大分别能达到449.05、126.07、532.83μg plant-1,生物富集量系数及转运量系数均随土壤镉浓度的增加而降低。在土壤镉浓度不高于75 mg kg-1时,牛繁缕生物富集量系数大于1 g plant-1,但各个镉处理下的转运量系数均小于1。由此可见,牛繁缕是一种镉富集植物,具有较强的镉富集能力,可用于镉污染农田的修复。In this study, a pot experiment was c onducted to study the cadmium accumulation characteristics of Malachium aquaticum under different cadmium concentrations conditions. The results showed that the root biomass,shoot biomass and total biomass of M. aquaticum decreased with the increase of cadmium concentration in soil. The resistance coefficients of M. aquaticum were greater than 0.5 when the cadmium concentration in the soil was less than100 mg kg-1, and the maximum resistance coefficient was 0.931(soil cadmium concentration was 25 mg kg-1). The photosynthetic pigment synthesis of M. aquaticum was inhibited under different cadmium concentrations in soil, and the contents of chlorophyll b, carotenoids and total chlorophyll decreased with the increase of soil cadmium concentration, but chlorophyll a content and a/b value had the fluctuating trend. With the increase of cadmium concentration in soil, the cadmium contents in roots and shoots of M. aquaticum showed an increasing trend. When the soil cadmium concentration was 100 mg kg-1, the cadmium content in shoots of M. aquaticum was 118.94 mg kg-1,which was higher than cadmium hyperaccumulator critical value(100 mg kg-1). The root and shoot bioconcentration factors of M. aquaticum were greater than 1, but the translocation factor was less than 1. The cadmium accumulation of root, shoot and whole plant achieved the maximum of 449.05, 126.07 and 532.83 ug plant-1, respectively. The bioconcentration amount factor and translocation amount factor decreased with the increase of soil cadmium concentration. When the cadmium concentration in the soil was not more than 75 mg kg-1, the bioconcentration amount factor of M. aquaticum was greater than 1 g plant-1, but translocation amount factor was less than 1 under all of cadmium treatment. Therefore, Malachium aquaticum was a cadmium accumulator with a strong ability of cadmium enrichment, and it could be used for remediation of cadmium-contaminated farmland.

关 键 词：牛繁缕 镉积累特性 农田杂草 富集植物 

分 类 号：X53[环境科学与工程—环境工程] X173