宁夏荒漠草原土壤细菌与真菌群落对降水变化的响应  

Responses of soil bacterial and fungal communities to precipitation in the desert steppe ecosystem of Ningxia

作　　者：米扬 郭蓉 王媛[1,2] 王占军[3] 蒋齐[3] 俞鸿千[3] 马琨[1,2] MI Yang;GUO Rong;WANG Yuan;WANG Zhan-jun;JIANG Qi;YU Hong-qian;MA Kun(National Key Laboratory Breeding of Northwest Land Degradation and Ecological Restoration,Ningxia University,Yinchuan 750021,China;Key Laboratory for Restoration and Reconstruction of Degraded Ecosystem in Northwestern China of Ministry of Education,Ningxia University,Yinchuan 750021,China;Institute of Forestry and Grassland Ecology,Ningxia Academy of Agricultural and Forestry Sciences,Yinchuan 750001,China)

机构地区：[1]宁夏大学西北土地退化与生态恢复国家重点实验室培育基地,宁夏银川750021 [2]西北退化生态系统恢复与重建教育部重点实验室,宁夏银川750021 [3]宁夏农林科学院林业与草地生态研究所,宁夏银川750001

出　　处：《草业学报》2023年第11期81-92,共12页Acta Prataculturae Sinica

基　　金：宁夏干旱半干旱区林草资源保育与生态生产功能提升关键技术研究与示范项目(NGSB-2021-14);国家自然科学基金(31660132)资助。

摘　　要：细菌和真菌作为土壤主要微生物类群,在荒漠草原生态系统中随自然降水梯度变化的响应是否一致仍不清楚。为揭示自然降水变化对土壤细菌和真菌群落的影响机制,选取多年平均降水量为231(T_(0)),154(T_(1)),137(T_(2))和114 mm(T_(3))的4个宁夏荒漠草原国家监测点作为观测样地。基于IonS5^(TM)XL高通量测序方法,开展了降水变化对荒漠草原土壤细菌和真菌群落的影响差异研究。结果表明:荒漠草原土壤细菌总OTUs、真菌总OTUs总体上表现为随降水梯度的下降呈先上升后下降趋势。荒漠草原土壤细菌类群的主要优势菌门为变形菌门(Proteobacteria)、放线菌门(Actinobacteria)和酸杆菌门(Acidobacteria),土壤真菌类群的主要优势菌门为子囊菌门(Ascomycota)和担子菌门(Basidiomycota)。降水变化对细菌优势菌门(变形菌门、放线菌门、酸杆菌门)和部分非优势菌门[疣微菌门(Verrucomicrobia)]相对丰度影响显著(P<0.05);真菌优势菌门(子囊菌门、担子菌门)相对丰度受降水变化影响不显著,但非优势菌门[球囊菌门(Glomeromycota)]的相对丰度受降水变化影响显著(P<0.05)。与T_(0)处理相比,T_(1)、T_(2)和T_(3)处理下细菌和真菌的丰富度指数(Chao1指数和ACE指数)显著升高,细菌群落的Shannon-Wiener多样性指数也显著升高,但真菌的Shannon-Wiener多样性指数无显著变化。驱动细菌群落变化的环境因子为土壤全氮和速效磷,驱动真菌群落变化的环境因子为土壤全磷和有机质。植被因子(生物量)和土壤因子(土壤养分)共同参与解释了降水变化对荒漠草原土壤细菌群落和真菌群落的调控过程,其中土壤因子起主导作用。研究结果表明,土壤细菌和真菌群落对生物和非生物因子的变化有不同的响应机制,反映了荒漠草原土壤微生物应对降水变化具有不同的适应策略。Bacteria and fungi are the most important soil microbial groups,but their response mechanism to precipitation change in desert grassland ecosystems remains unclear.We investigated the response mechanism of soil bacterial and fungal communities to long-term precipitation differences in the desert grassland of Ningxia.Four national monitoring sites with different precipitation characteristics in the desert grassland of Ningxia were selected for study.Precipitation treatments were:231(T_(0)),154(T_(1)),137(T_(2))and 114 mm(T_(3))annually.Using the IonS5^(TM)XL high-throughput sequencing method,the differences in bacterial and fungal populations in soil under the long-term precipitation regime changes in desert grassland were investigated.It was found that bacterial and fungal operational taxonomic units(OTUs)generally showed an initial increase and then a decreasing trend with progressive decrease in precipitation along the treatment gradient.Proteobacteria,Actinobacteria and Acidobacteria were the predominant bacteria soil communities at the phylum level,and Ascomycota and Basidiomycota were the predominant fungal communities in this desert grassland.Differences in precipitation significantly affected the relative abundance of dominant bacteria(Proteobacteria,Actinobacteria and Acidobacteria)and non-dominant bacteria(Verrucomicrobia)at the phylum level,and also the relative abundance of Glomeromycota(P<0.05),but did not significantly affect the relative abundance of the predominant fungal communities(Ascomycota,Basidiomycota).Compared with treatment T_(0),the richness indexes(Chao1 index and ACE index)of bacteria and fungi were significantly higher in treatments T_(1),T_(2) and T_(3),and the Shannon-Wiener diversity index of bacteria was also significantly higher.However,the Shannon-Wiener diversity index of fungi was not significantly affected.The total nitrogen and available phosphorus were the most important environmental factors driving bacterial community change,and total phosphorus and soil organic matter(OM)

关 键 词：荒漠草原 降水变化 微生物群落 适应策略 

分 类 号：S812.2[农业科学—草业科学]