不同粒径商品聚乙烯微塑料对...菜种子发芽和幼苗生长的影响_栗敏.pdf

生态毒理学报Asian Journal of Ecotoxicology第 17 卷 第 6 期 2022 年 12 月Vol.17,No.6 Dec.2022 基金项目:国家自然科学基金面上项目(42077115);山东省自然科学基金杰出青年基金(ZR2021JQ13)第一作者:栗敏(1996),女,硕士研究生,研究方向为新型污染物的生态毒性效应,E-mail: *通信作者(Corresponding author),E-mail:DOI:10.7524/AJE.1673-5897.20211220001栗敏,刘强,曹东东,等.不同粒径商品聚乙烯微塑料对 2 种蔬菜种子发芽和幼苗生长的影响J.生态毒理学报,2022,17(6):419-433Li M,Liu Q,Cao D D,et al.Effects of different commercial polyethylene microplastics with different particle sizes on seed germination and seedlinggrowth of two vegetables J.Asian Journal of Ecotoxicology,2022,17(6):419-433(in Chinese)不同粒径商品聚乙烯微塑料对 2 种蔬菜种子发芽和幼苗生长的影响栗敏1,刘强1,曹东东1,邵梦莹1,刘一帆1,罗先香1,2,李锋民1,2,郑浩1,2,*1.中国海洋大学近海环境污染控制研究所,海洋环境与生态教育部重点实验室,青岛 2661002.青岛海洋科学与技术国家实验室,海洋生态与环境科学功能实验室,青岛 266237收稿日期:2021-12-20 录用日期:2022-04-05摘要:陆地生态系统中微塑料(MPs)污染问题已成为全球关注的热点环境问题。MPs 对土壤生物的影响表现出生态毒性和遗传毒性,但不同粒径 MPs 对典型农作物生长的影响有待深入研究。因此,本研究通过发芽实验和盆栽实验研究不同粒径(23m、54 m 和 155 m)的聚乙烯 MPs(PE-MPs)在不同污染浓度下(0.1%、0.5%、1%、2%和 5%(mm)对西红柿(Lycopersiconesculentum)和辣椒(Capsicum annuumL.)种子发芽、幼苗生长及根系发育的影响。结果表明,3 种粒径的 PE-MPs 对 2 种作物发芽的影响存在差异。对西红柿,不同粒径的 PE-MPs 在高浓度(5%)下均显著抑制了种子发芽,降低了种子活性,但并无显著的粒径差异。对辣椒而言,不同粒径的 PE-MPs 在 5%的暴露浓度下均显著降低了辣椒种子活性,且 23 m 的 PE-MPs 抑制程度最大,但仅23 m 和54 m 的 PE-MPs 显著抑制了种子的发芽。盆栽实验表明,23 m 的 PE-MPs 在5%的暴露浓度下显著抑制了西红柿和辣椒幼苗的生长,54 m 和 155 m 的 PE-MPs 对其影响较小。此外,对根系发育而言,2%和 5%浓度的 23 m的 PE-MPs 暴露下,西红柿根系变得细长,但对辣椒根系无显著影响。PE-MPs 对 2 种作物发芽的抑制效应可能是由于其在种子表皮和根毛上积累,造成物理堵塞,抑制了对水分和营养物质的吸收导致的。PE-MPs 还可能通过释放添加剂对植物生长造成毒性,抑制其对水分及营养元素的吸收,改变幼苗酶活性,扰乱作物中的氧化还原稳态抑制植物幼苗生长。本研究为深入评估农业生态系统中不同粒径 PE-MPs 污染的生态风险提供了基础数据。关键词:微塑料;种子萌发;植物毒性;根系损伤;生态风险文章编号:1673-5897(2022)6-419-15 中图分类号:X171.5 文献标识码:AEffects of Different Commercial Polyethylene Microplastics with DifferentParticle Sizes on Seed Germination and Seedling Growth of Two Vegeta-blesLi Min1,Liu Qiang1,Cao Dongdong1,Shao Mengying1,Liu Yifan1,Luo Xianxiang1,2,Li Fengmin1,2,Zheng Hao1,2,*1.Institute of Coastal Environmental Pollution Control,Key Laboratory of Marine Environment and Ecology,Ministry of Education,Ocean University of China,Qingdao 266100,China2.Laboratory for Marine Ecology and Environmental Science,Qingdao National Laboratory for Marine Science and Technology,Qing-dao 266237,China420 生态毒理学报第 17 卷Received 20 December 2021 accepted 5 April 2022Abstract:Microplastics(MPs)pollution in terrestrial ecosystems has become a hotspot environmental issue.MPsin soils showed ecotoxicity to soil organisms,but the effects of MPs with different particle sizes on the growth oftypical crops are still unclear.Therefore,three polyethylene MPs(PE-MPs)with different particle sizes of 23 m,54 m and 155 m were selected to investigate their effects on tomato(Lycopersicon esculentum)and pepper(Capsicum annuumL.)including seed germination,seedling growth and root development under the different expo-sure concentrations of 0.1%,0.5%,1%,2%and 5%(m/m)using seed germination experiments and pot experi-ments.The results showed that the effects of PE-MPs with three different particle sizes on the germination of twocrops were different.For tomato,PE-MPs with different particle sizes significantly inhibited the germination andactivity of seeds at the highest concentration of 5%,but little difference was observed among the different sizedMP treatments.For pepper,PE-MPs with the different particle sizes significantly decreased the seed activity at thehighest exposure concentration of 5%,and 23 m PE-MPs showed the greatest inhibited effect on the seedlinggrowth.However,only 23 m and 54 m PE-MPs posed significant inhibition on the germination of pepper.In thepot experiment,23 m PE-MPs significantly inhibited the seedling growth of tomato and pepper under the highestexposure concentration,while 54 m and 155 m PE-MPs showed non-significant effect on the seedling growth oftomato and pepper.In addition,tomato roots were elongated under the exposure of 23 m PE-MP at the concentra-tion of 2%and 5%,but little effect were observed on the pepper root growth.The inhibitory effect of PE-MPs onthe germination of the two crop seeds could be ascribed to the accumulation of PE-MPs on the seed epidermis androot hair,which consequently could result in the physical blockage and inhibition of water and nutrient uptake.Inthe soil environment,PE-MPs could inhibit plant uptake of water and nutrients,reduce the enzyme activity of seed-lings,disrupt the redox homeostasis,thereby inhibiting the seedling growth.These findings provide the scientificbasis for evaluating the ecological risk of MPs in agricultural ecosystems.Keywords:microplastics;seed germination;phytotoxicity;root damage;ecological risk 微塑料(MPs)是指环境中5 mm 的塑料碎片或颗粒1-2,按其来源分为初生 MPs 和次生 MPs1。初生 MPs 指直接排入环境中的塑料颗粒,如个人洗护产品中的塑料微珠和工业研磨剂等,次生 MPs 指环境中的塑料在物理、化学、生物因素的作用下破碎分解形成的小碎片和微粒3。由于其独特的非天然聚合物结构以及含有丰富的异生物质,MPs 具有“不易消亡或环境持久”的物理和化学综合效应4,可能对全球生态环境健康构成重大风险,已经成为全球性的热点环境问题。最早 MPs 的研究主要聚焦于海洋和淡水生态系统5,陆地生态系统中 MPs 污染的研究起步较晚。然而,与水生生态系统相比,陆地生态系统可能更容易受到 MPs 的污染。据估计,每年释放到陆地生态系统中的 MPs 丰度可能是释放到水生生态系统中的 MPs 的 4 倍 23 倍6。另外,陆地生态系统中的 MPs 也是水生生态系统中 MPs污染的重要来源7。土壤 MPs 的污染现象广泛存在,已在耕地、林地、草地和建设用地等土壤中均被检出8。其中,农田土壤系统被