微塑料对樱桃萝卜生长的影响

Effects of the growth of cherry radish affected by different microplastics

为探究微塑料对蔬菜生长发育的影响,以菜地土壤中普遍存在的聚乙烯(polyethylene,PE)和聚丙烯(polypropylene,PP)为目标污染物,以根菜类蔬菜樱桃萝卜(Raphanus sativus L.var.radculus pers)为供试蔬菜,基于种子萌发试验和土培试验初步探究了不同粒径、不同浓度的微塑料对萝卜生长发育的影响。结果表明:PE和PP对萝卜种子的发芽率无显著影响,仅5 g·L^(-1)的PP对萝卜幼苗芽长具有显著(P <0.05)抑制作用;两种微塑料均能附着在萝卜幼苗根表面,并显著(P <0.05)抑制幼苗根的伸长,且该抑制作用随着微塑料粒径减小、浓度升高而增强。土培条件下,PE和PP并未影响萝卜叶片光合色素的合成;PE对萝卜叶鲜重、根茎鲜重无显著影响,但PP造成萝卜产量显著(P <0.05)降低,表明不同类型微塑料对萝卜生长的影响不同。推断其原因是PE和PP对土壤结构和肥力的影响不同,从而导致萝卜的生物量产生了不同的表现。

To explore the effects of microplastics(MPs) on the growth of vegetables,taken two commonly detected MPs(i.e.polyethylene(PE) and polypropylene(PP)) in soils of cherry radish(Raphanus sativus L.var.radculus pers) as the target contaminants,selected cherry radish as the tested materials,the effects of the tested MPs on the growth of radish were preliminary studied based on the seed germination test and the soil culture experiment.The results showed that PE and PP had no effect on the germination rate of radish seeds.The addition of MPs to the water had no significant effect on the bud length of seedlings,except for the treatment with 5 g·L^(-1) of PP;the two tested MPs attached to the radish roots,and significantly(P < 0.05) inhibited the growth of the root,moreover,this inhibitory effect enhanced with increasing MPs concentrations and decreasing MPs particle sizes.PE and PP had no significant impact on the photosynthetic pigment content in the cherry radish,furthermore,PE induced negligible impacts,while PP significantly(P < 0.05) decreased the radish biomass,which indicated that the effects of MPs on the radish growth were related to MPs types.A plausible explanation is that PE and PP have various effects on soil structure and/or fertility,thereby resulting in different performances of radish biomass after exposure to PE and PP.