龟裂链霉菌M527抗真菌物质的分离鉴定及其在黄瓜枯萎病防治中的应用

为探明龟裂链霉菌Streptomyces rimosus M527发酵液中抗真菌成分及其对黄瓜枯萎病菌的拮抗作用，本试验以黄瓜枯萎病菌F. oxysporum f. sp. cucumerinum为活性跟踪指示菌。首先，通过有机溶剂萃取、硅胶柱层析、DiaionHP-20凝胶柱层析、制备型HPLC对活性化合物进行分离纯化，结合MS、1H-NMR和13 C-NMR波谱数据对活性化合物结构进行解析，从菌株M527的发酵液中分离得到活性化合物与龟裂杀菌素一致。结果表明，当龟裂杀菌素浓度为2.20 mg/L时，能够完全抑制黄瓜枯萎病菌的孢子萌发；当龟裂杀菌素浓度为8.78 mg/L时，黄瓜枯萎病菌的菌丝生长受到明显抑制。17.56 mg/L的龟裂杀菌素溶液与传统农药乙蒜素（80%）1000倍稀释液进行黄瓜盆栽试验，施药后14和21 d龟裂杀菌素的治疗效果分别为78.3%和70.6%，乙蒜素的治疗效果为66.7%和42.7%。

Identification of Antifungal Compound from Streptomyces rimosus M527 and Its Application in Biocontrol of Pathogenic Fusarium Wilt on Cucumber

Using Fusarium oxysporum f. sp. cucumerinum as an indicator strain, the antifungal active component from the fermentation broth of the strain Streptomyces rimosus M527 were identified and its antagonistic activity against fusarium wilt of cucumber were investigated. After the fermentation broth of S. rimosus M527 was extracted with organic solvent and separated on silica gel column chromatography, the active compound was further purified by chromatography on Sephadex LH-20 and preparative HPLC. Based on the structure analyses of the active compound by MS, ¹H-NMR and ¹³C-NMR spectroscopy, the active compound was identified to be rimocidin. Rimocidin at the concentration of 2.20 mg/L could completely inhibit the spore germination of F. oxysporum f. sp. cucumerinum, while the hyphal growth could be inhibited by 8.78 mg/L rimocidin. Greenhouse experiments on potted cucumber plants demonstrated that therapeutic effect of rimocidin was better than that of ethylicin. After treatment for 14 d and 21 d, the therapeutic effect of rimocidin (17.56 mg/L) against F. oxysporum f. sp. cucumerinum in potted cucumber seeding was 78.3% and 70.6%, respectively, while the 1000 fold diluted ethylicin (80%) was 66.7% and 42.7%, respectively.