| Heavy metal pollution of metal mining and the surrounding soil has been a serious problem, because of its toxicity to environment and humans. Continue to search for and study rapidly growing and accumulator or hyperaccumulator plants and it was significance to phytoremediation and restoration of the ecological environment. This study selected Crassocephalum crepidioides (Benth.) S. Moore of two lead-zinc mine areas in Han Yuan as the research object, The main results were as follows:(1) Under the Cd stress,Crassocephalum crepidioides (Benth.) S. Moore showed some tolerance characteristics; with the increase of stress concentration, Cd accumulation capacity was gradually increased. Under the highest concentrations,height, root length, biomass and chlorophyll were significantly decreased compared to control(P<0.01),With the increase of concentration,peroxidase(POD) in leaves increased at first then decreased,dismutase(SOD) and catalase(CAT) were gradually decreased.In Cd treatments,various concentrations of Cd contents showed cell wall>organelles>cytosol;Cd contents in plants were increased with increasing concentration;The maximum content of shoot reached 1289.48mg kg-1, The maximum accumulation in plants was 1.24 mg plant-1; TF and BCF were both greater than 1.(2) Under the Pb stress, The two Crassocephalum crepidioides (Benth.) S. Moore showed different tolerance characteristics; with the increase of stress concentration, Pb accumulation capacity was gradually increased. Root length and plant height of FQ were gradually decreased with the increase of concentration, while, WS showed a gradual upward trend; Biomass of shoots were higher than that in roots of FQ and WS; Chlorophyll content were the smallest under the highest Pb concentration;The activities of POD and SOD of FQ increased at first then decreased, while, WS were gradually increased; CAT in higher concentration were both significantly decreased compared to lower concentration (P<0.05). Pb content was the highest in cytosol (64.43%) of FQ, but the cell wall (51.33%) of WS. The maximum content reached 128.71 mg kg-1,67.42 mg kg-1 in shoots and 747.84 mg kg-1,1136.41mg kg-1 in roots respectively of FQ and WS.The maximum accumulation in plants were 0.23mg(FQ) and 1.6mg(WS);The TF and BCF were both lower than 1.(3) Under the Zn stress. The two Crassocephalum crepidioides (Benth.) S. Moore showed the similar tolerance characteristics; with the increase of stress concentration, accumulation capacity was gradually increased. Various treatments, root length (FQ) and WS) and plant height (WS) were higher than control. Biomass of shoots were both higher than that in roots, when in the maximum concentrations they were 0.06 g (FQ) and 0.19g(WS); Chlorophyll content was the smallest under the highest concentration; The maximum activities of POD were 731.16 Ug-1 FW(T7),955.79 Ug-1 FW(T3) respectively; Under the highest concentration, SOD activity of FQ was the lowest (120.34 Ug-1 FW), while, WS was the highest(160.97 U g-1 FW). With the increase of concentration, the activity of CAT (FQ) in leaves increased at first then decreased, while, WS were gradually increased.Under the highest concentrations, Zn contents were both the highest in the cytosol. The maximum content reached 3155.63 mg kg-1,3331.40 mg kg-1 in shoots and 4877.10 mg kg-1,7018.18mg kg-1 in roots respectively of FQ and WS.The maximum accumulation in shoots were 3.28mg(FQ) and 2.74(WS);The TF were both lower than The BCF.In summary,Crassocephalum crepidioides (Benth.) S. Moore had a strong accumulation ability of Cd, while, some tolerance and accumulation ability of Pb and Zn. It had a certain function to contaminated soil repair according the accumulation, content of roots, biomass and the good growth conditions. |
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