硒纳米颗粒对两种叶菜作物肥料效应的田间试验研究

为探究农田环境下施用硒纳米颗粒(Se NPs)相比于传统硒肥(亚硒酸钠)对叶菜类作物生物量和品质的影响，在无锡滨湖区和苏州昆山市两片农田分别种植小油菜和生菜两种叶菜类作物，Se NPs土施浓度为0.05 mg/kg，对比分析叶菜类作物的根系参数(根长、根表面积、根体积)、生物量、抗坏血酸(Vc)含量、代谢产物种类和丰度. 结果表明:Se NPs可以显著促进叶菜类作物根系生长，提高小油菜(108.2%)和生菜(90.9%)生物量. Se NPs可以提高小油菜对铁(Fe)的倾向性吸收(48.1%)和生菜对锰(Mn)的倾向性吸收(72.2%)，有助于提高叶菜类作物的光合作用. Se NPs处理下的小油菜和生菜可食用部位硒含量水平高于0.30 mg/kg(以干质量计). 与之相比，同浓度的亚硒酸钠对叶菜类作物的促生效果不明显. 此外，Se NPs可以提高叶菜类作物体内Vc水平，其中小油菜Vc水平提高了127.5%，生菜Vc水平提高了23.1%. 代谢组学分析发现Se NPs使小油菜氨基酸和类黄酮的相对丰度提高约22.7%和37.1%. 对农田施用Se NPs的可行性进行评估发现，相比于亚硒酸钠，Se NPs降低了土壤中硒残留量并提高了土壤氮素的利用效率. 因此，与传统硒肥相比，农田施用Se NPs可以提高叶菜类作物的生物量和品质，并减少可能存在的环境风险. 

Field Study on Fertilizer Effect of Selenium Nanoparticles on Two Leafy Vegetables

The purpose of this study was to investigate the effect of selenium nanoparticles (Se NPs) on the biomass and quality of green leafy vegetables in farmland. Two fields (i.e., Binhu, Wuxi and Kunshan, Suzhou) were selected to grow green leafy vegetables, namely Brassica chinensis L. (rapeseed) and Lactuca sativa L. var. ramosa Hort (lettuce). The results of previous experiments indicated that the optimum concentration for soil application was 0.05 mg/kg. In this study, the root parameters (root length, root surface area, root volume), biomass, ascorbic acid (Vc) content, metabolite species and abundance of green leafy vegetables were analyzed. The results demonstrated that Se NPs could significantly promote root growth of green leafy vegetables. Se NPs increased the biomass of rapeseed (108.2%) and lettuce (90.9%). Specifically, Se NPs promoted the edible parts of green leafy vegetables containing more than 0.30 mg/kg dry weight of Se. In contrast, the conventional selenium fertilizer (sodium selenite) did not promote the growth of green leafy vegetables. Additionally, Se NPs improved the photosynthesis by increasing Fe content in rapeseed (48.1%) and Mn content in lettuce (72.2%). Moreover, Se NPs increased Vc levels in rapeseed (127.5%) and lettuce (23.1%). Metabolomics analysis showed that Se NPs significantly increased the relative abundance of amino acids (22.7%) and flavonoids (37.1%) in rapeseed. Compared with sodium selenite, Se NPs not only reduced the residual content of Se in soil, but also improved the utilization efficiency of soil nitrogen. Therefore, Se NPs can improve the biomass and quality of green leafy vegetables and reduce the potential environmental risks.