玉米植株各器官中重金属含量相关性的研究

为探讨大宗粮食作物玉米植株各器官中重金属含量的相关性,选择6个玉米品种进行盆栽实验。盆栽试验的土壤来自西南某省铅锌矿区。研究结果表明,(1)6个供试品种植株籽粒中,Ni、Pb、Zn的含量全部超标;部分品种玉米中的Cd含量超标;6个供试品种植株玉米中的Cr、Cu含量全部达标。(2)重金属含量在玉米各器官中存在交互效应;如,供试植株叶片中Cu与Ni、Pb与Zn分别存在显著正相关;在供试植株的叶片和茎秆中,Cd、Pb、Zn三者的含量呈显著性正相关。(3)金属Ni在供试植物茎秆与籽粒中存在交换的情况;金属Pb的含量在供试植株根部与茎秆的差异较大,其可能原因是植株茎秆对铅的吸收达到了饱和上限;金属Zn的含量在植株籽粒与茎秆中的差异较大,主要是因为Zn在玉米植株内的移动性强,且Zn最容易在籽粒中积累。

Research on the Correlation of Heavy Metal Content in Different Organs of Corn Plant

In order to investigate the correlations of heavy metal content in different organs of corn plants, 6 varieties of corn plants are selected for pot experiments. The soil is from a lead-zinc mining area in a southwest province. The result of experiments shows that, firstly, the contents of Ni, Pb, and Zn in seeds of the selected six corn plants are higher than national standard, the content of Cd in some corn plants are higher than national standard and the content of Cr and Cu in six corn plants all meet national standard. Secondly, there is interaction effect among the heavy metal content in different organs. In the leaves of the selected corn plants, the content of Cu and Ni, Pb and Zn are significantly and positively correlated. In the leaves and stalks of the selected corn plants, the contents of Cd, Pb, Zn are significantly and positively correlated. Thirdly, there is exchange of Ni between stalks and seeds. There is large difference of Pb content between roots and stalks of the selected corn plants, probably due to the absorption of Pb by stalks has met the saturation limit. There is large difference of Zn content between seeds and stalks of the selected corn plants, because of the high mobility of Zn in corn plants and easily accumulated in seeds.