摘要： 为了研究中药内生菌对植物病害真菌的拮抗效果，以云雾龙胆为材料进行试验，筛选到1株有拮抗作用的内生菌XJ01，通过形态观察、生理生化实验和16S rDNA系统进化分析，鉴定其为成团泛菌。试验结果表明，该菌株的发酵上清液对黄瓜褐斑病菌的生长有显著的拮抗作用，拮抗活性物质在20℃和30℃时活性较强，高于40℃则活性降低。在pH值为5～10之间均有抑菌活性，对低pH值更敏感；在30℃条件下，50μg／mL的蛋白酶K处理2h可以使其抑菌活性完全丧失；摇瓶发酵24h时，内生菌XJ01的抑菌活性最高。盆栽试验表明，内生菌XJ01对黄瓜褐斑病的发生具有明显的抑制作用。

关键词: 龙胆, 内生菌, 黄瓜褐斑病菌, 拮抗作用

Abstract: In order to study the antagonism effect of endophyte from Chinese traditional herb against plant path- ogenic fungi,experiment was done with Gentiana nubigena as material. The results showed that strain XJ01 was iso- lated. According to the characteristics of morphology, physiology and biochemistry tests and the comparison of 16S rDNA sequence, strain XJ01 was identified as Pantoea agglomerans. The fermentation broth of XJ01 showed activities against Corynespora cassiicola. In the conditions of 20℃ and 30℃, the antibiotic activity substance was higher. The antibiotic activity reduced when the temperature was higher than 40℃. The antibiotic active substance was stable in the pH range from 5 to 10, but more susceptible to lower pH. The antifungal activity lost under the treatment with 50 μg/mL proteinase K in the conditions of 30℃,longer than 2 h. The results of shaking flask fer- mentation curves showed antibiotic activities reached the maximum at 24 h. The result of potted experiment showed that XJ01 also had obvious antagonism activities against Corynespora cassiicola on the cucumber leaf.

Key words: Gentiana, Endophyte, Corynespora cassiicola, Antagonism

中图分类号: 

• S435