生物菌剂与土壤熏蒸互作对三七土壤微生物群落结构的影响

Effect of interaction between biocontrol agents and soil fumigation on soil microbial community structure in Panax notoginseng

【目的】探究棉隆熏蒸配施生物菌剂对三七根际土壤微生物群落结构和土壤基础理化性质的影响,为优化三七种植管理模式提供依据。【方法】以土壤条件(熏蒸)和处理方式(添加生物菌剂)为两个处理因素设计随机区组试验,检测土壤基础理化性质并利用高通量测序技术分析不同处理因素对土壤微生物群落结构的影响,解析土壤主要理化性质与菌群的关联。【结果】土壤熏蒸使细菌群落中的变形菌门、放线菌门和拟杆菌门的丰度上升,并降低了芽单胞菌门和酸杆菌门的丰度。担子菌门和子囊菌门在所有处理组中均为丰度最高的优势真菌门。非熏蒸+菌剂组细菌α多样性最高,熏蒸后添加生物菌剂会降低真菌α多样性。同样处理方式下熏蒸地pH和有效氮含量显著低于非熏蒸地,同样土壤条件下添加生物菌剂使土壤速效磷和速效钾下降。有效氮和pH与微生物群落结构的相关性最强。添加生物菌剂可以有效降低镰刀菌属、链格孢属、柱孢属、小不整球壳属等三七根腐病病原菌丰度,并提高假单胞属、溶杆菌属、伯克氏菌属等有益菌属的丰度。相同土壤条件下添加生物菌剂均能使被孢霉属、镰刀菌属、曲霉属、青霉属、枝孢属等熏蒸地优势菌属的丰度显著降低。【结论】非熏蒸地施加生物菌剂可以改善三七种植过程中土壤酸化问题。添加生物菌剂对微生物多样性的改变在不同土壤条件下的影响不一致。总体来说,生物菌剂的施用可以改善三七种植地土壤的微生物群落结构,为防控三七根腐病提供了一种有效方法。

【Objective】The present paper aimed to investigate the effect of biocontrol agents with dazomet on soil microbial community struc⁃ture and basic physicochemical properties in order to pave a way for good management in Panax notoginseng cultivation.【Method】A random⁃ized group experiment was designed with edaphic condition(fumigation)and treatment(biocontrol agents)as the two treatment factors.The basic physicochemical properties of the soil were detected and the effect of different treatment factors on the structure of the soil microbial community was analyzed using high throughput sequencing techniques to determine the association between the main physicochemical proper⁃ties of the soil and the bacterial community.【Result】Soil fumigation increased the abundance of the Proteobacteria,Actinobacteriota and Bacteroidota in the bacterial community,at the same time reduced the abundance of the Gemmatimonadota and Acidobacteriota.The Ascomy⁃cota and Basidiomycota were the dominant fungal phylum with the highest abundance in all treatment groups.The soil pH after fumigation significantly decreased compared to that of non⁃fumigated soil.The bacterial alpha diversity index increased more significantly in the non⁃fumiga⁃ted soil added biocontrol agents group,whereas the addition of biofungicide after fumigation reduced fungal alpha diversity.The pH and avail⁃able nitrogen levels were significantly lower in fumigated sites than in non⁃fumigated sites under the same treatments,while the addition of biofumigants reduced soil available phosphorus and potassium under the same soil conditions.The pH and available nitrogen levels were sig⁃nificantly lower in fumigated sites than in non⁃fumigated sites under the same treatments,while the addition of biofumigants reduced soil a⁃vailable phosphorus and potassium under the same soil conditions.Available nitrogen and pH contributed to the strongest correlation with mi⁃crobial community structure.The addition of biocontrol agents effectively reduced the abundance of Fusarium,Cylindrocarpon,Alternaria and Plectosphaerella and increased the abundance of beneficial genera such as Pseudomonas,Lysobacter and Burkholderia.The addition of biocon⁃trol agents under the same soil conditions significantly reduced the abundance of Moritierella,Fuarium,Aspergillus,Penicillium,Cladospori⁃um which were dominant genera in the fumigated sites.【Conclusion】Non⁃fumigated land applying biocontrol agents could improve soil acidi⁃fication during P.notoginseng cultivation.The effect of the biocontrol agents on the alteration of microbial diversity was inconsistent under dif⁃ferent soil conditions.Overall,the application of biocontrol agents could improve the microbial community structure of the soil in P.notogin⁃seng cultivation sites and provide an effective method for the prevention and control of P.notoginseng root rot.