盐分胁迫下番茄盐分离子和重金属的分布特征

采用盆栽试验方法研究了不同盐分含量处理下番茄不同器官盐分离子(Na+、K+、Ca2+)和重金属离子(Cd2+、Pb2+、Cr2+、Zn2+、Cu2+、Ni2+)的分布特征,探讨盐分离子对番茄不同器官吸收重金属离子的影响机制,为重金属污染盐渍土壤的农业可利用性评价提供科学依据。结果表明,番茄根、茎、叶和果实Na+含量均随盐分含量增加而增加;番茄根K+含量随盐分含量增加小幅上升,茎K+含量则显著下降,叶K+含量无显著变化;番茄各器官Ca2+含量随盐分含量增加无明显变化。番茄根Cd、Pb、Cr、Zn和Cu含量以及番茄茎、叶Cd含量均随盐分含量增加而增加;番茄根Ni含量、番茄茎叶Pb、Cr、Ni、Zn和Cu含量以及番茄果实各重金属含量受盐分含量变化影响不大。因此,土壤盐分含量的增加对番茄根部吸收重金属(Ni除外)有促进作用。

Distribution Characteristics of Salt Ions and Heavy Metals in Tomato Under Salinity Stress

The distribution of salt ions(Na+,K+,Ca2+) and heavy metal ions(Cd2+,Pb2+,Cr2+,Zn2+,Cu2+,Ni2+) in different organs of tomatoes grown in the soils with eight salinity levels was surveyed using a pot experiment.The influence of salt ions on uptake of heavy metal by tomato was investigated.The results showed that Na+ contents within roots,shoots,leaves and fruits increased as soil salinity increased.K+ contents in roots rose slightly,K+ contents in shoots decreased significantly,while contents of K+ in leafs remain unaltered from treatment two to treatment eight.Ca2+ contents in different parts of tomato also didn’t change along with the soil salinity.The contents of Cd,Pb,Cr,Zn and Cu in roots,and Cd in shoots and leaves increased along with the rise of soil salinity.However,the contents of Ni in roots,Pb,Cr,Zn,Cu and Ni in shoots and leaves and all six heavy metals within fruits were not significantly influenced by soil salinity.It was concluded that the increase of soil salinity had positive effect on the uptake of heavy metals by the roots of tomatoes,except for Ni.The results provide some useful scientific information for the agricultural land use of saline soils polluted by heavy metals.