氮添加对不同坡度退化高寒草甸土壤真菌多样性的影响  

Effect of Nitrogen Addition on Soil Fungal Diversity in a Degraded Alpine Meadow at Different Slopes

作　　者：苏晓雪 李希来[1] 李成一[1] 孙华方 SU Xiao-xue;LI Xi-lai;LI Cheng-yi;SUN Hua-fang(College of Agriculture and Animal Husbandry,Qinghai University,Xining 810016,China)

机构地区：[1]青海大学农牧学院,西宁810016

出　　处：《环境科学》2022年第11期5286-5293,共8页Environmental Science

基　　金：国家自然科学联合基金项目(U21A20191);青海省自然科学基金创新团队项目(2020-ZJ-904);三江源国家公园联合研究专项(LHZX-2020-08);高等学校学科创新引智计划项目(D18013);青海省科技创新创业团队项目。

摘　　要：为明确不同坡度退化高寒草甸土壤真菌多样性对外源氮添加的响应规律,选取三江源区果洛州不同坡度退化程度相近的高寒草甸,进行外源氮添加试验,探讨不同氮添加水平:低等量氮添加(LN,2 g·m^(-2))、中等量氮添加(MN,5 g·m^(-2))和高等量氮添加(HN,10 g·m^(-2))对不同坡度退化草地土壤真菌多样性的影响.结果表明:(1)土壤中真菌分布类群集中于子囊菌门(Ascomycota)、担子菌门(Basidiomycota)、被孢霉门(Mortierellomycota)和球囊菌门(Glomeromycota),其中优势菌门为子囊菌门和担子菌门.子囊菌门、根肿黑粉门和油壶菌门等相对丰度在不同坡度间差异显著(P<0.05).而同一坡度不同氮添加处理下真菌各门丰度变化差异均不显著.(2)优势属为被孢霉属和Archaeorhizomyces,它们对不同坡度和不同氮添加水平的响应无差异性.(3)已鉴定95个菌属在不同坡度间存在显著差异(P<0.05).(4)一些相对丰度<1%的属在同一坡度不同水平氮添加间存在显著差异(P<0.05).(5)α和β多样性分析整体表现为在不同坡度和不同氮添加水平下土壤真菌群落无差异性.表明退化高寒草甸土壤真菌对外源氮添加的响应不敏感.This study proposed nitrogen addition experiments to analyze the effects of exogenous nitrogen addition on soil fungal diversity in alpine meadow.All the experiments were performed in degraded alpine meadow with two different slopes(gentle slope and steep slope)in Guoluo Prefecture of the Sanjiangyuan Region,and the sequence and analysis of ITS of soil fungi were performed using MiSeq PE250 sequencing technology.Comparative analysis was carried out with three nitrogen addition levels on soil fungal diversity in degraded grassland with different slopes,which included low nitrogen(LN,2 g·m^(-2)),middle nitrogen(MN,5 g·m^(-2)),and high nitrogen(HN,10 g·m^(-2)).The results showed that:(1)the distribution groups of fungi in the soil were Ascomycota,Basidiomycota,Mortierellomycota,and Glomomycota,and the dominant bacteria was Ascomycota.(2)The dominant genera were Mortierella and Archaeorhizomyces,and there were no differences in response to different slopes and nitrogen addition levels.(3)A total of 95 genera(Gibberellum,Preussia,etc.)were identified and significantly differed between two different slopes(P<0.05).(4)Bacteria with a relative abundance less than 1%had significant differences in nitrogen addition at different levels on the same slope(P<0.05).(5)In addition,the analyses ofαandβdiversities showed that soil fungal community structure was stable under different slopes and nitrogen addition levels.Exogenous nitrogen supplementation significantly improved the relative abundance of non-dominant fungal communities without destroying soil fungal community structure.

关 键 词：草地退化 外源氮输入 真菌多样性 高通量测序 坡度 

分 类 号：X171[环境科学与工程—环境科学]