摘要
为全面认识微塑料对草地农业生态系统的毒性效应和生态风险,以低密度聚乙烯(mLDPE)和聚乳酸(mPLA)2种不同类型的微塑料为试验对象进行盆栽试验,探究不同浓度下(0.1%、0.5%、1%、5%、10%,w/w,质量分数)两种类型的微塑料对紫花苜蓿生长和生理特性的影响。研究结果发现:相较于对照组,高浓度(10%)处理下,mPLA处理组紫花苜蓿生物量、总叶绿素含量和净光合速率显著降低,mLDPE处理组则是地上生物量与净光合速率显著降低;超氧化物岐化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性和丙二醛(MDA)含量随微塑料添加浓度升高而增加,mPLA处理组中SOD、CAT活性和MDA含量在10%浓度时分别显著提高了56.68%、85.63%和67.30%,mLDPE处理组中仅有SOD和POD的活性在10%浓度时影响显著。结果表明,微塑料添加对紫花苜蓿的毒害作用与微塑料的类型和浓度有关。高浓度mPLA能够损伤植物光合系统,影响植物的光合作用,对植物造成氧化损伤,从而抑制紫花苜蓿植株生长,其影响强于mLDPE。
A pot experiment was conducted under controlled conditions to comprehensively understand the toxic effects and ecological risks of microplastics on the grassland agro-ecosystem.Two types of microplastics,low density polyethylene(mLDPE)and polylactic acid(mPLA),were added to soil at five different doses(0.1%,0.5%,1%,5%,10%,w/w,dry soil weight).The growth and physiological characteristics of alfalfa(Medicago sativa)plants growing in these treatments were evaluated and compared with those of plants in the control(no microplastics).The results showed that a high concentration(10%)mPLA reduced the biomass,total chlorophyll content,and net photosynthetic rate of alfalfa plants,while mLDPE significantly decreased the aboveground biomass and net photosynthetic rate of alfalfa plants.The malondialdehyde(MDA)content and the activities of superoxide dismutase(SOD),peroxidase(POD),and catalase(CAT)increased as the dose of MPs increased.Compared with the control,the 10%mPLA treatment group showed a 67.30%higher MDA content and 56.68%and 85.63%higher activities of SOD and CAT,respectively.Among the mLDPE treatments,only the 10%dose significantly affected SOD and POD activities.The results of this study show that the toxic effect of microplastics on alfalfa is related to both the type and concentration of the microplastics.High concentrations of mPLA strongly affected alfalfa plants by damaging the photosynthetic system,decreasing plant photosynthesis,and causing oxidative damage,resulting in growth inhibition,which had a stronger influence than mLDPE.
作者
李超男
王磊
周继强
赵长兴
谢晓蓉
刘金荣
LI Chao-nan;WANG Lei;ZHOU Ji-qiang;ZHAO Chang-xing;XIE Xiao-rong;LIU Jin-rong(State Key Laboratory of Grassland Argo-ecosystems,College of Pastoral Agriculture Science and Technology,Lanzhou University,Lanzhou 730020,China;Gansu Nonferrous Engineering Survey,Design and Research Institute,Lanzhou 730000,China;College of Pharmacy,Gansu University of Traditional Chinese Medicine,Lanzhou 730000,China)
出处
《草业学报》
CSCD
北大核心
2023年第5期138-146,共9页
Acta Prataculturae Sinica
基金
自然资源部高寒干旱区矿山地质环境修复工程技术创新中心2021年度开放基金(HHGCKK2105)
甘肃省教育厅科技成果转化项目(2017D-16)
中央引导地方科技发展资金项目(22ZY2QG001)资助。
关键词
微塑料
紫花苜蓿
光合作用
抗氧化酶活性
microplastic
Medicago sativa
photosynthesis
activity of antioxidant enzyme
