龙江河河岸带撑篙竹根际与非根际土壤细菌群落特征

Characteristics of Soil Bacterial Communities in Rhizosphere and Bulk Soil of Bambusa pervariabilis McClure in the Riparian Zone of Longjiang River

关键词:  河岸带  撑篙竹  根际土壤  细菌群落组成特征  微生物多样性

Key words:  riparian zone  Bambusa pervariabilis McClure  rhizosphere soil  characteristics of bacterial community composition  microbial diversity

摘要:

为探究龙江河河岸带撑篙竹(Bambusa pervariabilis McClure)根际与非根际土壤细菌群落组成特征，揭示土壤细菌群落的相互作用与功能特征，以及影响细菌群落组成的环境因素，本研究开展该区域土壤理化环境因子调查，并进行土壤细菌群落高通量测序分析。结果表明，撑篙竹根际土壤pH值、氨氮(NH⁺₄-N)、硝氮(NO^-₃-N)和速效磷(Available Phosphorus,AP)均低于非根际土壤，水分含量(Moisture Content，MC)和土壤有机质(Soil Organic Matter，SOM)含量则高于非根际土壤，部分理化指标之间存在显著相关性。α多样性分析表明，撑篙竹根际土壤细菌群落丰富度较非根际土壤高，而多样性较非根际土壤低；放线菌门(Actinobacteriota，26.93%)、变形菌门(Proteobacteria，17.63%)、Patescibacteria(4.28%)、黏球菌门(Myxococcota，3.25%)和蓝藻门(Cyanobacteriota，2.65%)等5个门，以及γ-变形菌纲(Gammaproteobacteria，9.56%)、α-变形菌纲(Alphaproteobacteria，8.06%)、酸微菌纲(Acidimicrobiia，3.64%)、KD4-96 (2.97%)、Polyangia (2.64%)、Saccharimonadia (2.65%)和蓝藻纲(Cyanobacteria,2.58%)等7个纲在根际土壤中均表现出一定程度的富集现象。单因素网络分析表明，相比于非根际土壤，根际土壤细菌类群之间相互作用更复杂、联系更紧密。京都基因与基因百科全书(Kyoto Encyclopedia of Genes and Genomes，KEGG)功能注释表明，细菌群落功能通路主要为新陈代谢和环境信息处理。相关性分析表明，土壤细菌群落相对丰度主要与土壤pH值和MC存在显著相关性。根据上述结果，龙江河河岸带撑篙竹根际土壤细菌群落主要受到土壤pH值和MC影响，与碳、氮、磷、硫、铁等元素循环有关，可能在促进植物生长和环境保护方面发挥重要作用。

Abstract:

In order to explore the characteristics of soil bacterial community composition in rhizosphere and bulk soil of Bambusa pervariabilis McClure in the riparian zone of Longjiang River,reveal the interaction and functional characteristics of soil bacterial community,and the environmental factors affecting the composition of bacterial community,in this study,the physical and chemical environmental factors of soil in this area were investigated,and the high-throughput sequencing analysis of soil bacterial community was carried out. The results showed that the pH value,NH⁺₄-N,NO^-₃-N and Available Phosphorus (AP) in rhizosphere soil were all lower than those in bulk soil,while the contents of Moisture Content (MC) and Soil Organic Matter (SOM) were higher than those in bulk soil. There was a significant correlation between some physical and chemical indexes. Alpha diversity analysis showed that the richness of bacterial community in rhizosphere soil of B.pervariabilis McClure was higher than that in bulk soil,but the diversity was lower than that in bulk soil. 5 phyla such as Actinobacteriota (26.93%),Proteobacteria (17.63%),Patescibacteria (4.28%),Myxococcota (3.25%) and Cyanobacteriota (2.65%),and 7 classes such as Gammaproteobacteria (9.56%),Alphaproteobacteria (8.06%),Acidimicrobiia (3.64%),KD4-96 (2.97%),Polyangia (2.64%),Saccharimonadia (2.65%) and Cyanobacteria (2.58%) all showed a certain degree of enrichment in rhizosphere soil. Single factor network analysis showed that the interaction between bacterial groups in rhizosphere soil was more complex and closely related than that in bulk soil.(Kyoto Encyclopedia of Genes and Genomes,KEGG) functional annotation showed that the functional pathways of bacterial community were mainly metabolism and environmental information processing. Correlation analysis showed that the relative abundance of soil bacterial community was significantly correlated with soil pH value and MC. Based on the above results,the rhizosphere soil bacterial communities of B.pervariabilis McClure in the riparian zone of Longjiang River is mainly affected by soil pH value and MC,and is related to the cycling of carbon,nitrogen,phosphorus,sulfur,iron and other elements,which may play an important role in promoting plant growth and environmental protection.