| Heavy metal pollution, especially cadmium（Cd） pollution, is one of the majorenvironmental pollutants of soil and has become a big obstacle to the sustainable development ofagriculture in China, and the accumulation of heavy metals in vegetables that planted in urbanshows a rising trend. Artemisia selengensis, which is regarded as a kind of health care vegetables,has a long edible history and is the common wild vegetable planted in Jianghuai region. Thispaper chossed4Artemisia selengensis（Fuqiu Artemisia selengensis, Dayeqing Artemisiaselengensis, Bai Artemisia selengensis and Qingbai Artemisia selengensis） as the study object, bythe means of simulated wastewater irrigation, studying the effects of water control （continuousflooding irrigation,intermittent irrigation and controlled moisture irrigation） on Artemisiaselengensis growth and its uptake of Cd on Cd contaminated soil, understanding the changes ofCd contents and available Cd contents in soil through the pot-culture experiment. The aims ofthis paper was to understand the dynamic changes of Cd in the soil-Artemisia selengensis systemunder different water conditions, find out the species variation of Cd accumulation andtranslocation in Artemisia selengensis of different varieties and assess the satety of Artemisiaselengensis as stem-leafy vegetable to eat. The main research results were as follows:（1）When Cd treatments were greater than0.5mg·kg-1, the stem Cd concentrations ofArtemisia selengensis exceeded the Safety requirments for non-environmental pollutionvegetable, which showed that the soil was not suitable for planting Artemisia selengensis, andwhen soil Cd content was slightly higher than the natural background value, Fuqiu Artemisiaselengensis could be choosed. Significant differences occurred in edible part（stem） Cdconcentrations,bioaccumulation factors （BFs） and translocation factors （TFs） among4Artemisiaselengensis（P<0.05）. As soil Cd treatment concentration increased from0.5mg·kg-1 to300mg·kg-1 the bioaccumulation factors （BFs） and the translocation factors （TFs） followed arise-fall pattern, and the bioaccumulation factors （BFs） was maxmium when soil Cd treatmentconcentration was100mg·kg-1, and the translocation factors （TFs） was maxmium when soil Cdtreatment concentration was150mg·kg-1. The bioaccumulation factors （BFs） were all greaterthan1.0, which showed the strong ability of Cd adsorption.（2）The Cd contents of Fuqiu Artemisia selengensis and Qingbai Artemisia selengensis weresignificantly increased in peak period along with growth time. In mature period the Cd contentsof Fuqiu Artemisia selengensis and Qingbai Artemisia selengensis were not significant at low Cdconcentrations and the Cd contents increased to the significant level when Cd concentrations insoil were higher. The Cd distribution in Artemisia selengensis was root>stem>leaf, and when soilCd concentrations exceeded100mg·kg-1,the ratio from root to stem and leaf decreased gradually.Correlation analysis showed that the Cd contentss in Artemisia selengensis had a strong positiverelationship with the Cd contents in soil in the same growth period, and the correlation of Qingbai Artemisia selengensis was greater than Fuqiu Artemisia selengensis′s.（3）The antioxidant enzyme activities in leaves of Fuqiu Artemisia selengensis and QingbaiArtemisia selengensis increased first and then decreased with the increase of Cd concentrations insoil, and the drop of the antioxidant enzyme activities in leaves of Fuqiu Artemisia selengensiswere greater than Qingbai Artemisia selengensis′s. The antioxidant enzyme activities in leaves ofArtemisia selengensis increased along with the growth period.（4）With the improvement of flooding degree, available Cd contents in soil were significantlydecreased （p<0.05） because of the chemical action of soil, and the Cd contents in root, stem andleaf of Fuqiu Artemisia selengensis and Qingbai Artemisia selengensis had strong positiverelationships with available Cd contents in soil. Compare to controlled moisture irrigation, thecontinuous flooding irrigation resulted in distinctly lower Cd contents in the root, stem and leaf.When total Cd contents in soil was1mg·kg-1, the Cd content in stem of Fuqiu Artemisiaselengensis decreased from1.0122±0.04mg·kg-1to0.3960±0.02mg·kg-1under continuousflooding irrigation, which reached the Safety requirments for non-environmental pollutionvegetable. |
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