红树植物苦郎树提取物及其活性成分对植物病原真菌的抑菌活性研究

采用活性跟踪法及色谱分离技术从红树植物苦郎树叶中分离获得2种抗菌化合物KLS -46和KLS-54,测定苦郎树甲醇提取物及2种化合物对西瓜枯萎病菌、芒果叶枯病菌、甘蔗凤梨病菌、香蕉炭疽病菌、梨黑斑病菌、梨褐斑病菌、柑橘疮痂病菌的抑菌活性.结果表明,苦郎树叶提取物对7种植物病原真菌的抑菌活性明显高于茎提取物和果提取物,10 g/L叶提取物对7种病原菌抑菌率为22.37％～100.00％.KLS-46对后5种病原菌菌丝生长的EC50值为9.79×10-3～7.88×10-2 g/L,KLS-54的EC50值为9.26×10-3～9.75×10-2g/L,2种活性成分对5种植物病原真菌菌丝的毒力相似.活性成分对甘蔗凤梨病菌、柑橘疮痂病菌和西瓜枯萎病菌的孢子萌发有较强的抑制活性,在浓度为0.25 g/L时,KLS -46的抑制率分别为98.31％、100.00％和98.15％,KLS-54的抑制率分别为99.83％、100.00％和99.33％.

Inhibitory Activities of Extracts and Active Ingredients from Mangrove Plant Clerodendrum inerme against Plant Pathogenic Fungi

Two antimicrobial compounds KLS-46 and KLS-54 were isolated from leaves of mangrove plant Clerodendrum inerme by activity-guided isolation method and chromatography,and the inhibitory activities of methanol extracts and the two compounds against plant pathogenic fungi were determined.The results showed that the inhibitory activity of leave extract was remarkably higher than that of stem and fruit extracts.The inhibitory rate of leave extract against Thielaviopsis paradoxa,Alternaria kikuchiana,Mycosphaerella sentina,Sphaceloma fawcettii,Glorosprium musarum,Pestalotia mangiferae and Fusarium oxysporum f.sp.niveum were 22.37%~100% at 10 g/L,respectively.The EC50 values of KLS-46 and KLS-54 to hyphae growth of the anterior five pathogens were 9.79×10-3~7.88×10-2 g/L and 9.26×10-3~9.75×10-2 g/L,respectively.The toxicity of the two compounds to the five pathogens was similar.KLS-46 and KLS-54 had obvious inhibition against spores germination of T.paradoxa,S.fawcettii and F.oxysporum f.sp.niveum,with the inhibitory rate of 98.31%,100.00% and 98.15% for KLS-46,and 99.83%,100.00% and 99.33% for KLS-54 at 0.25 g/L,respectively.The results suggested that the extract and the two compounds had high inhibitory activities against plant pathogenic fungi.