蜈蚣草对砷锑镉的富集效果及体内存在形态研究

    Study on Enrichment Effect and the Vivo Existing Form in Vivo of As, Sb and Cd in Pteris vittata L.

    • 摘要: 【目的】探究在水培条件下,蜈蚣草受到 As、Sb、Cd 单一胁迫及交互胁迫后,对其富集特征及体内的赋存形态变化。【方法】选用重金属耐受植物蜈蚣草为载体,利用改良霍格兰营养液水培 7 d,通过不同梯度As、Sb、Cd 胁迫探究富集特征,并探究浓度为 50 mg/L 时不同处理条件下 As、Sb、Cd 在蜈蚣草中的赋存形态特征。【结果】重金属单一胁迫下,蜈蚣草地下部 As、Sb、Cd 富集浓度最大值分别为 337.56、7 020.90、2 742.58 mg/kg,地上部最大富集浓度分别为 886.60、3 058.60、4 045.80 mg/kg,蜈蚣草仅对 As 的转移系数稳定> 1;在浓度 50 mg/L下,单一胁迫或交互胁迫时,蜈蚣草体内 As 乙醇态与盐酸态浓度占比为 69.49%~94.25%,Sb 残渣态浓度占比为47.48%~78.36%,Cd 盐酸态浓度占比为 93.67%~98.46%;加入 Sb 后,蜈蚣草地下部、地上部对 As 的吸附浓度分别提高 60.83、144.40 mg/kg,As、Cd 的加入能大幅降低蜈蚣草根、茎、叶中 Sb 乙醇态浓度,降幅为 72.9%~97.0%,As、Sb 的加入会促进蜈蚣草根部 Cd 盐酸态浓度,升幅达 38.2%~206.5%。【结论】蜈蚣草对 Sb、Cd 的富集能力较强,但仅为高富集作用。在胁迫浓度 50 mg/L 下,蜈蚣草体内 As 以乙醇提取态与盐酸提取态为主,Sb 以残渣态为主,Cd 以盐酸提取态为主,Sb 可以提高蜈蚣草对 As 的富集能力,As、Cd 对 Sb 毒性具有拮抗作用,As、Sb 对蜈蚣草根部 Cd 盐酸态有促进作用,蜈蚣草对 As、Sb 复合污染的土壤具有更好的修复能力。

       

      Abstract: 【Objective】 The study was conducted to explore the enrichment characteristics and extraction changes of Pteris vittata in vivo with the single and interactive treatment of As, Sb and Cd under hydroponiculture conditions. 【Method】 The heavy metal tolerant plant P. vittata was selected as the carrier, and it was cultivated in hydroponics for 7 days with the improved-hoagland nutrient solution. The enrichment characteristics of As, Sb and Cd in different concentrations under adversity stress was explored. And the morphological characteristics of As, Sb and Cd in P. vittata under different treatment conditions were studied when the concentration of 50 mg/L. 【Result】Under single heavy metal adversity stress, the maximum enrichment concentrations of As, Sb and Cd in the underground parts of the P. vittata were 337.56, 7 020.9 , 2 742.58 mg/kg, and the maximum enrichment concentrations in the aboveground parts were 886.6 , 3 058.6, and 4 045.8 mg/ kg, respectively. Only the transfer coefficient of the P. vittata to As is stably larger than 1. At the concentration of 50 mg/L and under the single stress or polymetallic interactive stress, the concentration of As in ethanol and hydrochloric acid in P. vittata was 69.49%-94.25%, the concentration of Sb residue was 47.48%-78.36%, and the concentration of Cd in hydrochloric acid state was 93.67%-98.46%. When Sb was added, the adsorption concentrations of the underground and aboveground parts of the P. vittata to As were increased by 60.83 mg/kg and 144.40 mg/kg, respectively. The addition of As and Cd significantly reduced the concentration of Sb in the roots, stems and leaves of the P. vittata by 72.9%-97.0%. The addition of As and Sb increased the concentration of Cd hydrochloric acid in the roots of the P. vittata by 38.2%-206.5%. 【Conclusion】P. vittata has a strong enrichment ability for Sb and Cd, but only a high enrichment effect. Under the adversity stress concentration of 50 mg/L, As in the P. vittata is mainly in a state of ethanol extraction and hydrochloric acid extraction, Sb is mainly in a state of residue form, Cd in a state of hydrochloric acid extraction condition. Sb can improve the enrichment ability of P. vittata to As. As and Cd are antagonistic to the toxicity of Sb, and As and Sb can improve the Cd in hydrochloric acid state of the P. vittata roots. P. vittata can better restore the soil polluted by As and Sb.

       

    /

    返回文章
    返回