芦蒿对Cd积累与转运的基因型差异研究

Genotypic Differences in Cd Accumulation and Translocation in Artemisia selengensis

为保障芦蒿作为茎叶菜食用的安全性,通过温室盆栽试验,研究了4种芦蒿对Cd积累与转运的基因型差异。结果表明,同一Cd处理水平下4种芦蒿品种干物重变化差异显著(P<0.05),且随着Cd处理水平的增加4种芦蒿品种干物重均呈现先上升后下降的趋势,在100 mg·kg-1时达到最大。随着土壤Cd处理浓度的增大,4种芦蒿叶片抗氧化酶活性呈现先上升后下降的趋势,且伏秋芦蒿和白芦蒿抗氧化酶活性下降幅度大于大叶青芦蒿和青白芦蒿。4种芦蒿基因型可食部分(茎)Cd含量、富集系数(BFs)和转运系数(TFs)存在显著的品种差异(P<0.05),且富集系数均大于1.0。当土壤Cd浓度超过0.5 mg·kg-1时,芦蒿茎中Cd含量均超过无公害蔬菜安全要求,说明该土壤已不适宜种植芦蒿,当土壤Cd含量略高于自然背景值时,则可以选择伏秋芦蒿。

Heavy metals may pose health risks through food chain. The accumulation of heavy metals by vegetable plants has genotypic dif- ferences. A pot-cuhure experiment was carried out to study genotypic differences in Cd accumulation and translocation in A rtemisia selen- gensis, a health-benefiting vegetable, At the same Cd level, the variation of dry weight of 4 Artemisia selengensis was significant （P〈0.05）. The dry weight of 4 A rtemisia selengensis followed a rise-fall pattern with Cd concentrations, with the greatest dry weight at 100 mg Cd· kg-1. Similarly, the activity of antioxidant enzyme in the leaves of 4 Artemisia selengensis increased at first and then decreased with increasing Cd. The decline in the antioxidant enzyme activity was greater in Fuqiu Artemisia selengensis and Bai Artemisia selengensis than in Dayeqing Artemisia selengensis and Qingbai Artemisia selengensis. Significant differences（P〈0.05 ） were observed in Cd concentrations in edible part（ stem ）, bioaccumulation factors （ BFs ） and translocation factors （TFs） among 4 A rtemisia selengensis. The BFs were greater than 1.0 for all 4 A rtemisia selengensis. The Cd concentrations in A rtemisia selengensis stems grown in soils with 〉0.5 mg Cd· kg-1 exceeded the Safety Standards for non-pollution vegetables, indicating that the soils was not suitable for growing A rtemisia s elengensis. Fuqiu A rtemisia selengensis should he choosed for soils containing Cd slightly higher than the natural background value.