一株生防真菌TRCC27001的鉴定及其抑菌特性

Identification of a biocontrol fungus TRCC27001 and its antifungal properties

通过平皿对峙法测定了菌株TRCC27001对12种常见植物病原真菌生长的拮抗作用,以及不同胁迫条件对菌株TRCC27001发酵液抑菌活性的影响;同时,通过形态学观察与分子生物学手段结合的方式,鉴定了菌株TRCC27001的种类.结果表明,菌株TRCC27001对12种病原真菌都有一定的拮抗作用,其中对黑腐皮壳菌和金黄壳囊孢菌落生长的抑制效果较强,对峙培养96 h后相对抑菌率分别达到6.39±1.22和2.29±0.19.以金黄壳囊孢为指示菌,筛选出TRCC27001的最佳发酵培养基为麸皮培养基,其无菌发酵液的抑菌率达79.40%,且其无菌发酵液的抑菌活性在不同胁迫条件(温度5～105℃,pH 2～12,紫外辐射时间0.5～2.0 h)下具有良好的稳定性.结合形态学特征、ITS序列及Tef1-α序列,将菌株TRCC27001鉴定为绿木霉(Trichoderma virens),是一株具有较高生防潜力的广谱性真菌.

Dual-culture method was used to evaluate antagonistic effects of strain TRCC27001 on 12 pathogenic fungi. The antifungal activity of sterile fermentation broth was tested under different stress conditions. Meanwhile, strain TRCC27001 was identified based on morphological features and molecular biology techniques. The results indicated that strain TRCC27001 had certain antagonism to 12 pathogenic fungi. Among them, it showed satisfactory antifungal activity on Cytospora ambiens and C.chrysosperma, with relative inhibitory rates of 6.39±1.22 and 2.29±0.19 after cultivation for 96 h, respectively. Using C.chrysosperma as indicator fungus, the optimal fermentation medium was screened as wheat bran medium. Also, its sterile fermentation broth showed an inhibitory rate of 79.40% against C.chrysosperma. In addition, the antifungal activity of the sterile fermentation broth of strain TRCC27001 was stable after being treated at 5-105 ℃, or under pH 2-12, or radiated by UV for 0.5-2.0 h. Finally, based on morphological features and Tef 1-α and ITS sequence analysis, strain TRCC27001 was identified as Trichoderma virens, which could be a potential biocontrol fungus against plant pathogenic fungi.