挺水植物水田芥对镉的积累特性研究  

CADMIUM ACCUMULATION CHARACTERISTICS OF EMERGED PLANT NASTURTIUM OFFICINALE R.BR.

作　　者：林立金[1,2] 罗丽[1] 廖明安[1] 张潇[1] 杨代宇 

机构地区：[1]四川农业大学园艺学院,四川雅安625014 [2]雅安水土保持生态环境监测分站,四川雅安625000

出　　处：《长江流域资源与环境》2015年第4期684-689,共6页Resources and Environment in the Yangtze Basin

基　　金：国家农业科技成果转化资金项目(2011GB2F000006)

摘　　要：通过前期的初步研究发现,挺水植物水田芥（Nasturtium officinale R.Br.）地上部分镉含量超过了超富集植物的临界值（100mg/kg）,可能是镉超富集植物。为进一步了解水田芥在不同镉浓度梯度条件下的镉积累特性,通过盆栽试验研究了不同土壤镉浓度（0、25、50、75、100mg/kg）对水田芥生长特性、镉耐性和镉积累特性的影响。结果表明：随土壤镉浓度的增加,水田芥根系和地上部分镉含量增大,分枝数量、根系生物量、地上部分生物量、抗性系数及叶绿素SPAD值均呈降低的趋势。当土壤镉浓度大于0mg/kg时,随着土壤镉浓度的增加,水田芥的根冠比呈增加的趋势。土壤镉浓度为50-100mg/kg时,水田芥地上部分镉含量均大于100mg/kg,最大值为214.84mg/kg（土壤镉浓度为100mg/kg）,地上部分富集系数（BCF）大于1,但转运系数（TF）小于1。在土壤镉浓度为50mg/kg时,水田芥地上部分镉积累量达到最大值,为192.233μg/株。因此,水田芥是一种镉富集植物,适合用于土壤镉污染浓度在50mg/kg以内的水田修复。The emerged plant Nasturtium officinale R.Br.is a wild vegetable widely distributed in Europe,Asia and North America,and can grow rapidly in nutritious water.In a preliminary study,the cadmium content in shoot of N.officinale reached 133.52mg/kg when the dose of cadmium was 60mg/kg in soil,exceeding the critical value of a Cd-hyperaccumulator（100 mg/kg）,indicating that this plant might be a Cd-hyperaccumulator. To further the understanding on the cadmium accumulation characteristics of N.officinale under various concentrations of cadmium and identify whether this plant is a Cd-hyperaccumulator,apot experiment with cadmium concentration gradient（0,25,50,75,100mg/kg）in soil was conducted to study the growth characteristics,the cadmium tolerance and the cadmium accumulation characteristics of N.officinale.The results were showed as follows.The cadmium contents in root and shoot of N.officinale increased with the increase of cadmium concentration in soil,while the number of branches,the root biomass,the shoot biomass,the chlorophyll SPAD value and the resistance coefficient decreased.The leaves of N.officinale appeared yellow when the concentration of cadmium in the soil was greater than 50 mg/kg,and the area of yellow leaf increased with the increasing cadmium concentration in soil,indicating that N.officinale had been seriously poisoned by cadmium at these high doses.When the cadmium concentrations in soil were greater than 0 mg/kg,the root/shoot ratio of N.officinale showed an increasing trend with the increasing concentration of cadmium in soil,indicating that N.officinale could increase the proportion of root biomass to enhance the tolerance to cadmium stress.The cadmium content in shoot of N.officinale exceeded 100mg/kg when the dose of cadmium was more than 50 mg/kg in soil,up to the maximum of 214.84 mg/kg（100 mg/kg cadmium in soil）.The shoot bioconcentration factor（BCF）of N.officinale was greater than 1and increased with the increase of cadmium concentration in soil.The translocation factor�

关 键 词：水田芥(Nasturtium officinale R.Br.) 镉 积累特性 

分 类 号：X173[环境科学与工程—环境科学] S647[农业科学—蔬菜学]