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为获得具有广谱抑菌活性的拮抗菌株,对海南多年连茬的健康香蕉园土壤进行微生物分离,并以香蕉枯萎病菌4号小种(Fusarium oxysporum f.sp.cubense Race 4)等9种病原菌为靶标菌株,采用平板对峙法、含药介质法、薄层层析法等对拮抗菌的抑菌活性进行评价,根据形态特征、培养性状、生理生化特征、细胞壁组成和16S rDNA序列分析对其进行鉴定。共分离得到放线菌25株,拮抗放线菌8株,其中B-03菌株对香蕉枯萎病菌4号生理小种菌丝生长和孢子萌发抑制率分别为85.43%和80.14%,对香蕉长形叶斑病菌等9种病原菌具有广谱抗性,菌丝生长抑制率、孢子萌发抑制率可达48.34%~85.43%和38.43%~80.14%。经鉴定该菌株为卢娜林瑞链霉菌(Streptomyces lunalinharesii),盆栽试验表明该菌株发酵液对香蕉枯萎病的防效达72.72%,具有良好的应用潜力。
In order to obtain the antagonistic strains with broad-spectrum antibacterial activities, the healthy banana garden soil in Hainan for several years was subjected to microbial isolation. Nine pathogenic bacteria, Fusarium oxysporum fspspubense Race 4, As the target strain, the antibacterial activity of the antagonistic bacteria was evaluated by plate confrontation method, drug-containing medium method and thin-layer chromatography. According to the morphological characteristics, culture traits, physiological and biochemical characteristics, cell wall composition and 16S rDNA sequence analysis, Identification. 25 strains of actinomycetes were isolated and 8 strains of antagonistic actinomycetes were isolated. The inhibitory rates of strain B-03 on mycelial growth and spore germination of Fusarium oxysporum 4 were 85.43% and 80.14%, respectively. Nine pathogenic fungi, such as leaf spot bacteria, had broad spectrum resistance. The mycelial growth inhibition rates and spore germination inhibition rates were 48.34% -85.43% and 38.43% -80.14%, respectively. The strain was identified as Streptomyces lunalinharesii. The pot experiment showed that the fermentation broth of this strain had a control effect of 72.72% against banana wilt disease and had good potential for application.