叶面喷施两种典型纳米材料对苋菜积累多环芳烃的影响

为探究叶面喷施硅、锌等是否能够减少作物对土壤有机污染物的吸收机理,选择纳米二氧化硅、纳米氧化锌以及对应的盐作为叶面喷施材料,考察了它们对苋菜生长和吸收累积多环芳烃(PAHs)的影响。结果表明:材料喷施未对植物叶绿素产生显著影响,但均增加了植物干质量。在S1处理中(低浓度污染处理),硅酸钠处理干质量增加了42%;在S2处理中(高浓度污染处理),硅酸钠、纳米二氧化硅、硫酸锌处理干质量分别增加了50.2%、64.0%和77.7%。在S1处理中,与对照(CK)相比,喷施硅酸钠、纳米二氧化硅、硫酸锌和纳米氧化锌处理的苋菜中荧蒽浓度分别降低了46.5%、35.3%、27.4%和25.8%,纳米二氧化硅处理使苋菜中芘的浓度降低了25.6%;在S2处理中,各处理未发生显著变化。研究表明,在一定的条件下,纳米氧化锌和纳米二氧化硅的喷施降低了苋菜对PAHs的累积。

Effects of foliar application of two typical nanomaterials on accumulation of polycyclic aromatic hydrocarbons in amaranth (Amaranthus tricolor)

Foliage spraying with silicon or zinc can significantly reduce the crop uptake of heavy metals in soil, but it has not been reported whether it can reduce the uptake of organic pollutants in soil by crops. In this study, two treatments with low(S₁)and high polycyclic aromatic hydrocarbons(PAHs)concentrations(S₂)were set. The effects of nano-SiO₂, nano-ZnO, or their corresponding salts on the growth of Amaranthus tricolor and PAHs accumulation were investigated. The results showed that the spraying of these materials had no significant effect on plant chlorophyll, but increased the plant biomass in dry weight. In the S₁ treatment, the biomass in the Na₂SiO₃ treatment increased by 42.0%; in the S₂ treatment, the biomass in the Na₂SiO₃, nano-SiO₂, and ZnSO₄ treatments increased by 50.2%, 64.0%, and 77.7%, respectively. In the S₁ treatment, compared with that of the control, fluoranthene absorption of Amaranthus tricolor was reduced by 46.5%, 35.3%, 27.4%, and 25.8% with foliage spraying of NaSiO₃, nano-SiO₂, ZnSO₄, and nano-ZnO, respectively. Compared with that of the control, the absorption of pyrene was reduced by 25.6%. In the S₂ treatment, no significant change occurred in each treatment. It was shown that under certain conditions, the spraying of nano-ZnO and nano-SiO₂ reduced the accumulation of PAHs in Amaranthus tricolor, which may be a new method to reduce PAHs accumulation in plants.