| "Juema" belongs to Rosacrae,Potentilla,Potentilla anserina L.is the translated term.Wild Juema root tuber is a resource plant with a long history in Qinghai,which can be used for both medicine and food.The economic value and ecological value of different varieties of Juema has a very broad prospect of development and utilization.Research contents: In this experiment,the content of heavy metals in cultivated Qinghai Juema No.1 was determined in different regions of Qinghai Province.Then,the effects of different heavy metals on the morphology of the plant and the accumulation of mercury,lead,cadmium and chromium in different parts of different varieties of Juema were studied by hydroponic culture with edible Juema(Qinghai Juema No.1,Qinghai Juema No.2)and ecological Juema as materials.It provides a theoretical basis for the area selection of edible Juema,and provides a basis for the remediation and further development of heavy metal contaminated soil by cological Juema.The main results:(1)The contents of heavy metals in Juema were significantly different under different environment conditions.4 and 2 regions in Qinghai Province with the contents of Cr and Pb were more than 1.0 mg/L,respectively.There was a significant positive correlation between them,but the linear correlation was weak.In Huangyuan,Menyuan and Xinghai experimental plots,the contents of heavy metals in Qinghai Juema No.1 were mercury,cadmium,arsenic,lead and chromium in the order from low to high,which did not exceed the national food heavy metal limit standards,so it was suitable to popularize Juema.There was a significant negative correlation between cadmium and arsenic content in the three places,but no correlation between other two heavy metals was found.(2)Different Juema varieties had different tolerance and enrichment ability to heavy metals.The semi-lethal dose of mercury,lead and cadmium were 50 mg/L ~ 100 mg/L,100 mg/L ~ 150 mg/L,20 mg/L ~ 30 mg/L for edible Juema,and 50 mg/L ~ 100 mg/L,150 mg/L,50 mg/L for ecological Juema,respectively.When the concentration of Cr reached 150 mg/L,the lethality rate of edible and ecological Juema were only 20% and 4%.Among the four heavy metals,cadmium and mercury have the strongest lethal effect on edilble and ecological Juema,respectively.Among the three varieties,Qinghai Juema No.1 has the highest fatality rate of cadmium,Qinghai Juema No.2 has the highest fatality rate of lead,mercury and chromium.(3)The increase of heavy metal concentration had an effect on the growth and development of Qinghai Juema No.1,Qinghai Juema No.2 and ecological fern plant.The overall trend of plant height and leaf length decreased(negative correlation),and the correlation of 10 growth indexes with 4 heavy metals in hydroponic culture solution from strong to weak was mercury,cadmium,lead and chromium in turn.(4)In the experiment of hydroponic culture,the contents of mercury,lead,cadmium and chromium in the control group,Qinghai Juema 1,Qinghai Juema 2 and ecotype Juema 2 did not exceed the standard,but the Juema was cultured for 3 weeks at the lowest concentration,which indicated that Juema had the enrichment effect on heavy metals.Different varieties of Juema have different enrichment rules for different heavy metals.Enrichment of mercury,lead,cadmium and chromium by Juema matches the quadratic function model(y = ax2 + bx + c,R2 > 85%);(5)Ecotype Juema absorbed and enriched the heavy metals in the hydroponic liquid,and achieved the function of repairing and purifying the hydroponic environment.The BCF of aboveground parts are lead,chromium,cadmium and mercury from 6.14 to 31.72,and the BCF of underground parts are lead,mercury,cadmium and chromium from 21.12 to 753.13.Therefore,it is necessary to detect the content of heavy metals in soil before cultivation in order to prevent the heavy metals of edible Juema from exceeding the standards,and if the ecological Juema is planted,it is possible to repair the pollution of heavy metals in soil. |
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