贵州草海流域三种不同植被类型根际土壤真菌结构组成和多样性

Community and diversity of rhizosphere soil fungi in three different vegetation types in Caohai Basin, Guizhou Province

为了解草海流域3种不同植被类型(湿地、草坡和灌木林地)根际土壤真菌结构组成和多样性的差异,采集3种植被根际土壤,利用第二代高通量测序技术,对土壤真菌结构组成及其多样性进行分析,测定土壤理化性质和酶活性,并与土壤真菌多样性进行相关性分析。结果表明:3种植被类型根际土壤真菌物种隶属于4个门、34纲、109目、250科、537属,其中灌木林地和湿地的真菌结构组成相似性较高,优势种群均为座囊菌纲Dothideomycetes,分别占21.18%和11.13%,而草坡优势类群为属级未确定的真菌,占29.26%;土壤真菌的多样性表现为灌木林地>草坡>湿地;植被根际土壤酶活性随土层加深逐渐降低,其中灌木林地根际土壤酶活性最高,湿地根际土壤酶活性最低,植被根际土壤真菌多样性和土壤全N、全K和速效K显著相关。3种不同植被类型根际土壤理化性质和酶活性与土壤真菌组成、丰度和多样性显著相关(P<0.05),不同植被类型凋落物归还土壤并改变根际土壤理化性质和酶活性,进而影响根际土壤真菌组成结构和多样性。

The differences of rhizosphere soil fungal composition and diversity among three different vegetation types(wetlands,grassy slopes,and shrublands)in the Caohai Basin were investigated by using second-generation high-throughput sequencing technology.Correlation between soil fungal diversity and physical and chemical properties and enzyme activities of the soil was analyzed.The results showed that rhizosphere soil fungi of the three vegetation types belonged to 4 phyla,34 classes,109 orders,250 families,and 537 genera,and the fungal community of shrubland and wetland was similar and the dominant populations belonged to Dothideomycetes,accounting for 21.18%and 11.13%of the total classes,respectively.The dominant taxa in grassy slopes are undetermined genera,accounting for 29.26%of the total genera.The diversity richness of soil fungi showed a tendency of shrubbery land>grass slope>wetland.Rhizosphere soil enzyme activity in the vegetations decreased with the depth of the soil layer.The rhizosphere soil enzyme activity was the highest in the shrubland and the lowest in the wetland.The fungal diversity of the rhizosphere soil was significantly related to soil total nitrogen,total potassium and available potassium.The physicochemical properties and enzyme activities of rhizosphere soil of the three different vegetation types were significantly related to the composition,abundance and diversity of soil fungi(P<0.05).The litter of different vegetation types brought about the differences of physicochemical properties and enzyme activity of the rhizosphere soil and thereby affected the composition and diversity of rhizosphere soil fungi.