| 摘要: |
| 【目的】探讨梵净山典型优势树种根系土壤细菌群落结构、多样性、生态系统功能及其不同树种间差异的环境驱动因子。【方法】以梵净山世界自然遗产地的丝栗栲、西南米槠、厚皮栲、长柄水青冈、云山青冈和亮叶水青冈6种优势树种为研究对象，通过高通量测序技术分析根系土壤细菌群落组成及其在树种间的多样性差异，并应用PICRUSt（phylogenetic investigation of communities by reconstruction of unobserved states）对功能基因进行预测，基于冗余分析或相关性分析揭示土壤细菌群落、功能基因及环境因子（气候因素和土壤化学性质）间的相互关系。【结果】土壤化学性质因树种不同而存在一定差异，梵净山6种优势树种根系土壤碱解氮（AN）、有效磷（AP）和速效钾（AK）含量分别为4.09~12.98，5.64~9.91和29.38~68.33 mg/kg；全氮（TN）、全磷（TP）和全碳（TC）含量分别为1.85~3.41，0.29~0.50 和33.01~85.77 g/kg；pH和C/N分别为4.45~4.82和17.19~27.58。高通量测序结果表明，从72份土壤样品中共鉴定出851个属的细菌，分属38个门、99个纲、238个目、394个科。在不同树种间，细菌群落组成存在一定差异，其中酸杆菌门、变形菌门和放线菌门是根系土壤细菌的主要优势门类，三者相对丰度之和的均值为88.27%。多样性分析表明，虽然不同树种根系土壤中的细菌群落在丰富度和多样性上表现出很高的相似性，但也存在一定差异，其中厚皮栲根系土壤的Chao1指数最高，为5 284.8；亮叶水青冈的Shannon指数最高，为9.1；而长柄水青冈的Chao1指数和Shannon指数均为最低，分别为4 469.8和8.5。PICRUSt功能预测表明，不同树种根系土壤细菌主要参与5类一级代谢通路及其下属的33个子功能代谢通路，其中厚皮栲和长柄水青冈的KEGG功能基因相对丰度明显高于其他树种。冗余分析显示，海拔(Alt)和土壤AN含量是驱动土壤细菌群落结构变化的关键影响因素。相关性分析表明，细菌多样性指数与年平均温度（MAT）、年均大气湿度（AAH）呈显著负相关，而与土壤全碳(TC)呈显著正相关；KEGG功能基因相对丰度与环境因子的相关性较弱，而与细菌门水平的相对丰度存在较强相关性。【结论】梵净山6种优势树种根系土壤的化学性质、细菌群落组成、多样性及KEGG功能基因相对丰度存在一定差异。Alt和土壤AN含量是不同树种根系土壤细菌群落结构产生差异的关键环境驱动因子，而KEGG功能基因相对丰度主要与细菌群落结构变化相关。 |
| 关键词: 优势树种 土壤细菌 群落组成 功能潜势 驱动因子 梵净山 |
| DOI：10.13207/j.jnwafu.2026.01.012 |
| 分类号: |
| 基金项目:贵州省教育厅创新群体重大研究项目（黔教合KY 字［2016］053号）；贵州省科技计划项目（黔科合基础［2019］1312,黔科合基础-ZK/［2023］一般465）；铜仁市科技计划项目(铜市科研［2024］33号);铜仁学院博士基金项目（trxyDH1525） |
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| Root soil bacterial community composition and functional potential prediction of typical dominant tree species in Fanjing Mountain |
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YANG Lilin1, HOU Jianwei2, XING Cunfang2, YIN Bo1, LIU Min1, WANG Zuhua1, TIAN Fengxia3
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1.College of Agroforestry Engineering and Planning,Tongren University,Tongren,Guizhou 554300,China;2.Inner Mongolia Academy of Agricultural and Animal Husbandry Sciences,Hohhot,Inner Mongolia 010031,China;3.School of Economics and Management,Tongren University,Tongren,Guizhou 554300,China
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| Abstract: |
| 【Objective】This research aims to explore the structure,diversity and ecosystem function of rhizosphere soil bacterial communities of typical dominant tree species in Fanjing Mountain and the environmental factors driving the differences among different tree species.【Method】With six dominant tree species in Fanjing Mountain World Natural Heritage Site,namely Castanopsis fargesii Franch.,Castanopsis cuspidate (Thunb.) Schott.,Castanopsis chunii Franch.,Fagus longipetiolata Seem.,Cyclobalanopsis sessilifolia (Blume.) Schott.and Fagus lucida Rehd.et Wils.,as the objects of the study,the composition of the rhizosphere soil bacterial communities and their differences in diversity among species were analyzed by high-throughput sequencing technology,and functional genes were predicted by applying PICRUSt (phosphatidic investigation of communities by reconstruction of unobserved states).The interrelationships among soil bacterial communities,functional genes and environmental factors (climatic factors and soil chemical properties) were revealed based on redundancy or correlation analyses.【Result】Soil chemical properties varied somewhat among different tree species.The soil available nitrogen (AN),available phosphorus (AP) and available potassium (AK) contents of the root of the six dominant trees in Fanjing Mountain ranged from 4.09 to 12.98, 5.64 to 9.91 and 29.38 to 68.33 mg/kg,respectively.The contents of total nitrogen (TN),total phosphorus (TP) and total carbon (TC) ranged from 1.85 to 3.41,0.29 to 0.50 and 33.01 to 85.77 g/kg,respectively.pH and C/N ranged from 4.45 to 4.82 and 17.19 to 27.58,respectively.High-throughput sequencing showed that a total of 851 genera of bacteria were identified from 72 soil samples,belonging to 38 phylum,99 classes,238 orders and 394 families.There were some differences in the bacterial community composition among different tree species and Acidobacteria,Proteobacteria and Actinobacteria were found to be the main dominant bacterial phyla in rhizosphere soil,with the average value of the sum of their relative abundance being 88.27%.The diversity study indicated that although the bacterial communities in the rhizosphere soil of different tree species showed high similarity in abundance and diversity,there were certain differences.The Chao1 index of the rhizosphere soil of Castanopsis chunii Franch.was the highest (5 284.8),and the Shannon index of Fagus lucida Rehd.et Wils.was the highest (9.1),whereas the Chao1 index and the Shannon index of the Fagus longipetiolata Seem.were both the lowest (4 469.8 and 8.5,respectively).PICRUSt functional prediction showed that the root soil bacteria of different tree species were mainly involved in five types of primary metabolic pathways and their subordinate sub-functional metabolic pathways of 33 types.Among all the tree species,the relative abundance of KEGG functional genes of Castanopsis chunii Franch and Fagus longipetiolata Seem.was significantly higher than those of other tree species.Redundancy analyses showed that alitude(Alt) and soil AN content were significant influencing factors driving the changes in soil bacterial community structure.Correlation analysis showed that the bacterial diversity index was significantly negatively correlated with mean annual temperature (MAT) and annual atmospheric humidity (AAH),while it was significantly positively correlated with soil total carbon(TC).The environmental factors were weakly related with relative abundance of KEGG functional genes,and were strongly correlated with the relative abundance of bacterial phylum levels.【Conclusion】There are certain differences in chemical properties,bacterial community composition,diversity and relative abundance of KEGG functional genes in the rhizosphere soils of the six dominant tree species in Fanjing Mountain.Alt and soil AN content are the key environmental factors driving the differences in the bacterial community structure of the rhizosphere soils of the different tree species,while the relative abundance of KEGG functional genes is mainly associated with the changes in the bacterial community structure. |
| Key words: dominant tree species soil bacteria community composition functional potential driving factor Fanjing Mountain |
