抗香蕉枯萎病菌的卢娜林瑞链霉菌的分离及防效鉴定

Isolation and Identification of Streptomyces lunalinharesii and its Control Effect on the Banana Fusarium Wilt Disease

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 broad spectrum antagonistic strains,we isolated 25 Actinomycetes strains and 8 antagonist strains from healthy soil that had been cropping banana plants for a number of years in Hainan Province using Fusarium oxysporum f. sp. cubense Race 4 and 8 other pathogens as indicative strains. The antibacterial activity of the antagonistic bacteria was evaluated by plate confrontation,containing medium and thin layer chromatography methods. One of the strains,designated B-03,showed a strong and stable control effect against nine pathogens with the inhibition of mycelium growth of 48.34% to 85.43%,and the inhibition of spore germination rate of 38.43% to 80.14%. It also inhibits mycelium growth and spore germination of F. oxysporum Race 4 by 85.43% and 80.14%,respectively. Based on the morphological characteristics,cultural characteristics,physiological and biochemical characteristics,cell wall composition and 16S rDNA sequence analysis,the strain was identified as Streptomyces lunalinharesii. Pot experiment showed that the control effect of the strain fermentation broth on banana Fusarium wilt reached 72.72%. Taken together,our results suggest that the strain S. lunalinharesii could provide a new resource for biological control of banana Fusarium wilt disease.