| Maize is one of the most important food crops in China,and it is also one of the crops with hyperaccumulative effect of heavy metal cadmium?Cd?.In this study,eight maize varieties,two with lower Cd bioaccumulative effect and six with the higher,screened out in the previous study,were selected for field trials in five different polluted areas.The aim of this study was to investigate the differences in the uptake of cadmium in different contaminated soils,to clarify the enrichment ability of high accumulated maize in different soils and the applicability of low accumulated maize to different polluted soils,and to ensure the safe production and utilization of maize in heavily polluted areas highly accumulated maize for heavy metal contaminated soil remediation provides a theoretical basis.Soybean,as one of the main sources of plant protein and vegetable oil,plays an important role on our diet,yet it is also a sensitive crop to Cd toxicity.In this experiment,15 soybean varieties were selected to compare the Cd uptake in three polluted areas.The aim is to study the similarities and differences of Cd uptake by different soybean varieties in different polluted areas,to clarify the Cd bioaccumulative characteristics of soybean,and lay the theoretical basis for soybean production in contaminated areas.The results are as follows:?1?The range of transport coefficient of Cd was 1.34 to 3.53 and 2.91 to 5.31 in the different polluted areas,and the enrichment coefficient was 1.33 to 4.27 and 1.74 to 3.88,which belonged to Cd accumulation Corn varieties.They are categorized as strong Cd-accumulative maize varieties and can be used for Cd-contaminated soil treatment.Their Cd concentration in grains is higher than the national food safety standards.?2?Huayu 8,Guangzinuo 6,Tianyunuo22 and Zhuyunuo1 Maize varieties grown in different polluted areas satisfy the National Food Safety Standards in grain Cd content,and thus are categorized as the low Cd cumulative varieties.The content of Cd in Jinxi and Yutian 1 in the low pollution area reached the national food safety standard,but the Cd content in the high polluted area far exceeded the national food safety standard.?3?Grown in different polluted areas,the order of Cd content in different organs of maize plant with high Cd accumulation was:stem leaf>root>grain,and the order of low Cd accumulation was:root>stem leaf>grain.?4?The average values of Cd,Pb and As in the eight maize varieties of the thermal power plant were 0.21 mg·kg-1,0.062 mg·kg-1and 0.036 mg·kg-1.Among Guang Hongnong 8,Zhu Yutian 1,Hua Cainuo 3 and JinXi,the content of Cd in maize grains of the three cultivars was much higher than that of the national food safety standard,and the other varieties were in line with the standard.These eight varieties of Pb,As content are in line with national food safety standards.The correlation analysis showed that there was no significant correlation between Cd,Pb and As contents.?5?The enrichment ability of Cd in Huaxia 5 soybean grain was significantly higher than that of other cultivars,and the Cd content in the different polluted areas was 0.41mg·kg-1to 1.56 mg·kg-1,more than 4 times of the national food safety standard.The remaining 14 soybean varieties in the Shangba Village sewage remediation irrigation area grain Cd content are all in line with national food safety standards,in the village of long-term sewage irrigation area,only Huaxia 2 in line with national food safety standards,Shaoguan thermal power plant in all the surrounding all varieties are beyond the national food safety standards.?6?The average contents of Cd contents in different types of maize grains were 0.21mg·kg-1,1.04 mg·kg-1and 0.02 mg·kg-1,respectively,in the long-term and non-polluted areas of Shangba Village.The average contents of Cd contents in the long-term sewage irrigation area and the pollution-clearing area were 0.71 mg·kg-1,0.28 mg·kg-1and 0.16mg·kg-1,respectively,in the surrounding area of the thermal power plant,The content of Cd in soybean seeds in the same polluted area was much higher than that in maize. |
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