不同马铃薯品种对Cd、Pb吸收累积的差异

Differences of Cadmium and Lead Absorption and Accumulation in Different Potato Varieties

采用田间试验法,以中南地区主要种植的11个马铃薯品种为研究对象,测定马铃薯植株各部位重金属Cd、Pb含量,探讨不同品种的马铃薯对Cd、Pb的吸收累积差异,为马铃薯的安全种植提供实践参考。结果表明:Cd—Pb复合污染下,马铃薯块茎鲜重、茎叶鲜重以及根、茎叶、块茎中Cd、Pb含量在品种间均表现出显著差异。11个马铃薯品种块茎Cd含量范围为0.39~0.67 mg/kg,超标率100%,块茎Pb含量为0.16~0.43 mg/kg,超标率81.8%。马铃薯各部位Cd、Pb含量均呈现根>茎叶>块茎的分布特点;马铃薯对Cd的富集系数为2.35~5.56,对Pb富集系数为0.11~0.22,马铃薯富集转运Cd的能力大于Pb。尽管复合重金属靶标危险系数(TTHQ)法评价显示,金湘等5种马铃薯的TTHQ值<1,对人体健康风险较小,但结合块茎Cd、Pb含量,建议污染区种植的马铃薯作为工业原料使用更安全。

Field experiments were conducted to study 11 common potato varieties in central south China.The contents of cadmium(Cd)and lead(Pb)in potato organs were determined to analyze the difference of Cd and Pb absorption and accumulation capacity in different varieties of potatoes.The achievement of this work could provide a practical reference for safe planting of potatoes in the areas soil polluted with heavy metals in central south China.The results showed that in the soil complexly polluted with Cd and Pb,the fresh weight of tuber,stem and leaf,and the contents of Cd and Pb in roots,stems and leaves,tubers of potato plants showed significant differences among 11 varieties.The contents of Cd in tuber ranged from 0.39 to 0.67 mg/kg,showing an exceeding the standard rate of 100%;the contents of Pb in tuber ranged from 0.16 to 0.43 mg/kg,exceeding the standard rate of 81.8%.The contents of Cd and Pb in different potato organs showed a distribution pattern as root>stem and leaf>tuber.The bioaccumulation factors of Cd and Pb in potato plants ranged from 2.35 to 5.56 and 0.11 to 0.22,respectively,indicating that bioaccumulation and translocation capacity of potato for Cd was greater than for Pb.Although the Total Target Hazard Quotient demonstrated that the TTHQ values of five kinds of potatoes such as Jinxiang were less than 1,the risk to human health was small,but combined with the Cd and Pb contents of tubers,it is recommended to be safer to use potatoes grown in contaminated areas as industrial raw materials.