【摘要】 [目的]本文旨在筛选复合微生物菌剂并研究其防控番茄青枯病的效果。[方法]从土壤中分离获得拮抗番茄青枯菌的放线菌及细菌各2株，依据菌株的形态特征、理化特征及16S rRNA基因序列对其进行初步鉴定；用透射电镜观察青枯菌经放线菌上清液处理前、后的细胞形态变化；定量测定细菌产SOD酶活性；利用番茄盆栽试验筛选及验证复合菌剂的防病效果；利用高通量测序探究复合菌剂对根际土壤细菌群落结构的影响。[结果]2株拮抗放线菌WL-3、WL-4初步鉴定为链霉菌（Streptomyces sp.）,2株拮抗细菌CW-02、XL-2初步鉴定为芽胞杆菌（Bacillus sp.）。菌株WL-3、WL-4发酵上清液与青枯菌共培养24 h后，经透射电镜观察，青枯菌细胞分泌的胞外多糖显著减少。芽胞杆菌CW-02及XL-2产SOD活性分别为120.88和116.72 U·mL^-1。利用育苗基质小盆栽试验筛选出最佳的菌剂组合为链霉菌WL-4+芽胞杆菌CW-02,经土壤盆栽试验验证复合菌剂（WL-4+CW-02）对番茄青枯病的防效为45.58%;高通量测序结果表明，施用复合菌剂能够增加番茄根际细菌α与β多样性，提高潜在有益细菌类群（Sphingomonas、Pseudomonas等）的相对丰度，降低劳尔氏菌属（Ralstonia）的相对丰度。[结论]施用复合菌剂（WL-4+CW-02）能够较好防控番茄青枯病并改善番茄根际细菌群落结构。更多还原

【Abstract】 [Objectives]The paper was aimed to screen the composite microbial agent and study its control effect on tomato bacterial wilt. [Methods]Two strains of antagonistic actinomycetes and bacteria were isolated from soil respectively. The strains were identified by morphology, culture characteristics, physiological and biochemical characteristics and 16 S rRNA gene sequence analysis. The enzyme activities of SOD produced by bacteria were detected by xanthine oxidase method. Pot experiment was used to screen out the composite microbial agent with good disease control effect. High throughput sequencing was used to explore the effect of composite microbial agent on bacterial community structure in tomato rhizosphere soil. [Results]Two actinomycetes and bacteria with good antagonistic effect on Ralstonia solanacearum were obtained, which were preliminarily identified as Streptomyces sp. WL-3,WL-4 and Bacillus sp. CW-02,XL-2. When the supernatants of strain WL-3 and WL-4 were co-cultured with R.solanacearum respectively, the morphological changes of R.solanacearum,were observed by transmission electron microscopy, and the secretion of extracellular polysaccharide decreased significantly. The SOD activitives of Bacillus sp. CW-02 and XL-2 were 120.88 and 116.72 U·mL^-1,respectively. The best combination of Streptomyces and Bacillus（WL-4+CW-02）was screened out by small pot experiment with seedling substrate, and the control effect on tomato bacterial wilt was 45.58%. The results of high-throughput sequencing showed that the application of composite microbial agent increased the α and β diversity of rhizosphere bacteria, increased the relative abundances of potentially beneficial bacteria groups（Sphingomonas,Pseudomonas etc.）,and decreased the relative abundance of Ralstonia. [Conclusions]Composite microbial agent（WL-4+CW-02）could better control tomato bacterial wilt, and improve the bacterial community structure of tomato rhizosphere.更多还原