【摘要】 以野生苗移栽的蜈蚣草为试材 ,通过盆栽试验研究了收获次数对蜈蚣草生长、砷吸收和植物修复效率的影响。结果表明 :在 3次收获中 ,随着收获次数的增加 ,不同砷浓度处理之间蜈蚣草生物量的差异逐步缩小 ;不加砷的对照处理中 ,每次收获后的砷吸收速率下降趋势 ,而在 3个加砷处理中 ,第 2次收获和第 3次收获的蜈蚣草的吸砷速率为 6 3～ 75 μg/ (plant· d)、4 4～ 5 5μg/ (plant· d) ,均显著高于第 1次收获时的吸收速率。表明多次收获并没有降低砷的积累速度。由此可见 ,通过适当增加蜈蚣草的收获次数是提高砷修复效率的一种策略更多还原

【Abstract】 Arsenic (As) contamination of soils is a major environmental problem both in China and in the world. Chinese brake (Pteris vittata L.), which has a strong ability to tolerate and hyperaccumulate As, is a good candidate for phytoremediation of arsenic-contaminated soils. To understand the processes of As hyperaccumulation by P. vittata and to take P. vittata into practice, a growing body of researches has been carried out on understanding the mechanisms of As tolerance and hyperaccumulation, including the As distribution, speciation, transformation and nutrient uptake. After solving some technical difficulties, such as seedling breeding, irrigation and fertilization, the field phytoremediation of As-contaminated soils by P. vittata in Chenzhou City, Hu′nan Province has been successfully carried out for the first time by Chen and his colleagues since 2000. However, the improvement of phytoextraction efficiency of As from fields is still a key problem in phytoremediation. Pteris vittata belongs to perennial plants, indicating that it can be harvested for several times during growth period. For the practical application, the total amount of As accumulation by P. vittata must be considered, which depended on the biomass and As concentration. But it is not clear if the As concentration in P. vittata would decrease with the increase times of harvesting. Therefore, the objective of this study is to understand the effects of harvesting on As accumulation and phytoextraction efficiency of P. vittata by pot experiment. When 0, 100, 300 and 800 mg/kg of As were added, the total amount of As accumulation by the shoots of P. vittata were 2.6, 10.5, 13.4 and 12.1 mg/pot, respectively. The As uptake rates by P. vittata in the first harvesting ranged from 20 to 35 μg/(plant·d), which was significantly lower than those of the second and third harvesting. Therefore, it showed that more harvesting would increase the As accumulation and phytoextraction efficiency of As of P. vittata, indicating harvesting was an economical and convenient way for the phytoremediation when utilized P. vittata to improve the phytoextraction efficiency of As.更多还原