不同冻融阶段表层季节冻土细菌群落结构和功能解析  

Analysis of bacterial community structure and functions in seasonally frozen soil in different phases of the freeze-thaw cycle

作　　者：关健飞 曹阳 徐鸿嘉 GUAN Jianfei;CAO Yang;XU Hongjia(School of History and Culture,Mudanjiang Normal University,Mudanjiang 157000,China)

机构地区：[1]牡丹江师范学院历史与文化学院,牡丹江157000

出　　处：《生态学报》2024年第13期5726-5734,共9页Acta Ecologica Sinica

基　　金：黑龙江省省属高等学校基本科研业务费科研项目(1451ZD003);国家自然基金面上项目(42271196);牡丹江师范学院国家级课题培育项目(GP2021004)。

摘　　要：冻土微生物对预测冻土和气候之间潜在反馈机制至关重要。为明确不同冻融阶段对冻土细菌群落的影响,揭示冻土性质变化与细菌群落之间的响应关系,选择黑龙江典型季节冻土表层土为研究对象并进行理化性质测定,采用16S rRNA高通量测序技术分析细菌群落结构和功能组成,通过冗余分析等方法探究土壤理化性质与细菌群落结构和功能之间的相关关系。结果表明:(1)不同冻融阶段对土壤pH和总磷含量影响不显著,完全冻结期土壤中机质和总氮含量显著高于冻融循环期(P<0.05)。(2)共获得OTU序列985111条,属于42个菌门,优势菌门中,放线菌门(Actinobacteria)相对丰度在完全解冻期显著高于冻融循环期和完全冻结期(P<0.05),变形菌门(Proteobacteria)、酸杆菌门(Acidobacteria)、绿弯菌门(Chloroflexi)相对丰度在不同冻融阶段未表现出显著性差异。不同冻融阶段对细菌Alpha多样性和Beta多样性影响显著,其中冻融循环期显著增加了细菌群落的多样性,完全冻结期则使Beta多样性发生显著变化。此外,完全冻结期对细菌丰度之间的正相关性以及群落的稳定性影响较大。(3)细菌群落功能共5418种,分属于6大类,其中新陈代谢功能占比最大,不同冻融阶段平均值占比75%以上。一级功能在完全冻结期和完全解冻期之间均具有显著性差异(P<0.05)。具有显著性差异的二级功能中,几乎均在完全冻结期和完全解冻期之间存在显著差异(P<0.05)。(4)土壤有机碳(SOC)、总氮(STN)、总磷(STP)是影响细菌群落结构组成和功能的主要环境因子,pH影响不显著。综上所述,不同冻融阶段(特别是完全冻结期)对细菌群落结构组成和功能具有显著影响,这种影响的变化与土壤性质SOC、STN、STP呈现显著正相关或负相关关系,研究结果为进一步研究气候变暖背景下黑龙江省季节冻土微生物的响应机制提供科学依据。Microorganisms in frozen soil play a crucial role in predicting the potential mechanism of response between the frozen soil and climate.This study was envisaged to reveal the influence of different stages of the soil freeze-thaw process on the bacterial community in frozen soil and analyze the response of the bacterial community to the dynamics of the frozen soil properties.We determined the physiochemical properties of the topsoil from typical seasonally frozen ground in Heilongjiang Province.16s rRNA high-throughput sequencing was performed to analyze the bacterial community structure and function.The correlation between the physicochemical properties of the soil and the bacterial community structure and function were investigated using redundancy analysis.The results showed that:(1) Different stages of the soil freeze-thaw process exhibited an insignificant impact on the soil pH and total phosphorus.The soil organic matter and total nitrogen during complete freezing were significantly higher than those during the transition stage(P<0.05).(2) A total of 985111 reads were obtained and clustered into operational taxonomic units(OTUs) belonging to 42 phyla.Among the dominant phyla,the relative abundance of Actinobacteria during the complete thaw was significantly higher than that during the transition and complete freezing stages(P<0.05).The relative abundance of Proteobacteria,Acidobacteria,and Chloroflexi did not differ significantly across the stages of the freeze-thaw process.The alpha diversity and beta diversity of the bacterial community varied significantly in the different stages of the freeze-thaw process.The bacterial community diversity was considerably increased during the transition stage,while the β-diversity changed dramatically during complete freezing,compared with other stages.Furthermore,complete freezing had a greater impact on the positive correlation between the abundance of the bacterial phyla and the bacterial community stability.(3) A total of 5418 pathways of the bacterial community wer

关 键 词：季节冻土 高通量测序 土壤理化性质 细菌群落 

分 类 号：S154.3[农业科学—土壤学]