【摘要】 为探究镉(Cd)污染土壤中农作物的食用安全性,以上海市常见农作物(青椒、黄瓜、豇豆、菠菜、花菜、西红柿、水稻和小麦)为实验材料,采用温室盆栽土培实验方法研究了不同土壤Cd含量梯级(0. 23、0. 6、1. 2、1. 8、2. 4和3. 0 mg·kg-1)下不同作物生物量变化以及可食部分Cd富集特征,建立不同种类作物与土壤Cd含量相关关系,探讨不同作物对应的土壤Cd安全限量值,筛选Cd低累积作物品种.结果表明:①随着土壤中Cd含量增加,作物地上生物量表现为先增加后减少,青椒耐受性最强,西红柿、菠菜耐受性最差.②不同作物可食部位Cd的富集系数由大到小依次为小麦>菠菜>水稻>青椒>花菜>西红柿>黄瓜>豇豆.③作物可食部分Cd含量与土壤中Cd含量都呈显著正相关(P <0. 05),相关系数大小依次为菠菜>小麦>西红柿>黄瓜>青椒>水稻>花菜>豇豆.④不同作物对应的土壤Cd安全限量值大小依次为:豇豆>黄瓜>花菜>青椒>西红柿>水稻>菠菜>小麦.依据作物对土壤中Cd的耐受性、富集能力及食用安全限量值,筛选出黄瓜、豇豆、花菜为Cd低累积品种.更多还原

【Abstract】 Pot-culture experiments were carried out in Shanghai to screen crop varieties with low bioaccumulation properties with respect to cadmium( Cd). Eight common crops,such as green pepper,cucumber,cowpea,spinach,cauliflower,tomatoes,rice,and wheat,were planted in contaminated soil with different Cd concentrations of 0. 23,0. 6,1. 2,1. 8,2. 4,and 3. 0 mg·kg-1 to investigate the effects on biomass,Cd accumulation characteristics,and edible risk safety. The results indicated that: ① With the increase in soil Cd content,the aboveground biomass of crops increased firstly and then decreased. The different crop types had different tolerance to Cd,with green pepper showed the strongest tolerance and spinach and tomato showed the least tolerance. ② The bioaccumulation factor of Cd in the edible parts of eight crops ranged in order of wheat > spinach > rice > green pepper > cauliflower >tomato > cucumber > cowpea. ③ Total Cd content in soil was significantly correlated with Cd content in the crops( P < 0. 05),and the order of the correlation coefficients was spinach > wheat > tomato > cucumber > green pepper > rice > cauliflower > cowpea. ④ The risk threshold value of Cd in soil based on the edible safety of different crops ranged in order of cowpea > cucumber > cauliflower > green pepper > tomato > rice > spinach > wheat. Cucumber,cowpea,and cauliflower were selected as the low-Cd-accumulating varieties according to their tolerance to soil Cd,bioaccumulation capacity,and edible risk threshold values.更多还原