【摘要】 【目的】从山橙(Melodinus suaveolens Champ. ex Benth)中分离对植物病原真菌具有拮抗活性的内生真菌,为研发新型高效生物农药提供理论依据。【方法】采用组织培养法对山橙进行内生真菌的分离与纯化,结合菌种形态学和18S rDNA序列比对对其内生真菌进行鉴定;采用平板对峙法和菌丝生长速率法测定内生真菌对香蕉枯萎病4号小种、香蕉炭疽病菌和火龙果溃疡病菌等13株供试植物病原真菌的抑菌活性。【结果】从山橙的根、枝和叶中分别分离得到4、5和11株共20株内生真菌,平板对峙测定结果显示其中的菌株M4对白腐盾壳霉菌、向日葵霜霉病菌、禾谷镰刀菌、茄子黄萎病菌、水稻稻瘟病菌和火龙果溃疡病菌等6株植物病原真菌的抑制率均在30.00%以上,表现出较好的抗菌活性。结合形态特征与18S rDNA序列分析鉴定,确定菌株M4为Phanerochaete sp.,其菌株发酵液在20 mg/mL浓度下对马铃薯黄萎病大丽轮枝菌、马铃薯黑白轮枝菌、禾谷镰刀菌、茄子黄萎病菌、西瓜枯萎病菌、马铃薯立枯丝核菌和香蕉枯萎病4号小种等7株病菌均具有一定的抑制作用,其中对禾谷镰刀菌的抑制效果最佳,抑制率为40.92%,显著高于对其他病原菌的抑制率(P<0.05)。【结论】山橙内生真菌富含抑菌活性菌株,蕴藏着潜在的抑菌活性物质,具有良好的应用前景。更多还原

【Abstract】 【Objective】Endophytic fungi with antifungi activity were isolated from Melodinus suaveolens Champ. ex Benth to explore its potential active substances,and it provides a reference for development of new high-efficiency biopesticides.【Method】Tissue culture method was used to isolate and purify the endophytic fungi from M. suaveolens,and the endophytic fungi were identified by morphological analysis and 18 S rDNA gene sequence comparison. The antifungal activities of the fungi against 13 species of plant pathogenic fungi such as Fusarium oxysporum f.sp.cubense special Race 4,Colletotrichum musae Berk. et Curt and Neocystidium dimidiatum(Penz.)Crous & Slippers were determined by plate confrontation and growth rate method.【Result】Twenty endophytic fungi were isolated from the roots,branches and leaves of M. suaveolens. Among them,M4 strain had above 30.00% inhibition rate against Coniothyrium diplodiella,Plasmopara halstedii(Farl.)Berl. and Fusarium graminearum Schwabe,Verticillium dahliae,Pyricularia grisea(Cooke)Sacc and N. dimidiatum,showing fine antifungal activities. Combined with morphological characteristics and 18 S rDNA sequence analysis,the strain M4 strain was identified as Phanerochaete sp.,which had inhibition effects on Verticillium dahliae Kleb,V. albo-atrum,F. graminearum Schwabe,V. dahliae,F. oxysporum f. sp. nibeum,Rhizoctonia solanikuhn and Fusarium oxysporum f. sp. cubense special Race 4 at the concentration of 20 mg/mL of fermentation broth. The inhibition effects on F. graminearum were the best and the inhibition rate was 40.92%,which was significantly higher than inhibition rates on other fungi(P<0.05).【Conclusion】M. suaveolens endophytic fungi contain antifungal strains,potential antifungal active substances and good promise for application.更多还原