【摘要】 为挖掘苹果树腐烂病的高效生防微生物资源，从抗病性较强的多种海棠树皮组织中分离筛选对苹果树腐烂病菌Valsa mali具有较强拮抗效果的内生真菌，基于形态学和分子生物学方法鉴定其分类地位，通过皿内对峙和离体枝条试验解析该生防菌及其发酵液对苹果树腐烂病的防治效果，并初步解析其抑菌机制。结果显示：从木瓜海棠Chaenomeles cathayensis树皮组织中分离得到了1株对苹果树腐烂病菌具有较好抑制效果的菌株MG2，抑制率达到82.25%；结合形态学特征和多基因序列比对将其鉴定为球毛壳菌Chaetomium globosum；菌株MG2对黑腐皮壳属Valsa真菌的菌丝生长具有特异性抑制作用，其中对苹果树腐烂病菌的抑制效果最显著，在对峙培养后菌丝分枝增多，形态发生明显变化。菌株MG2能够稳定定殖于苹果树皮组织中且无致病作用，并在定殖后可有效防控腐烂病的发生，防效达72.46%；其发酵液对苹果树腐烂病菌的菌丝生长和分生孢子萌发均有较好的抑制效果。与菌株MG2对峙培养后，苹果树腐烂病菌中与细胞组成和新陈代谢相关的基因表达水平均发生明显变化，细胞能够被台盼蓝染色，胞内还原糖含量显著升高，推测菌株MG2对苹果树腐烂病菌的细胞膜结构和能量代谢产生了严重影响。表明MG2可作为苹果树腐烂病绿色防控的候选微生物资源。更多还原

【Abstract】 To investigate the biocontrol microbial resources with high efficacy in preventing apple tree Valsa canker(AVC), this study isolated and screened endophytic fungi with significant inhibitory effects against V. mali from the bark tissues of diverse crabapple trees with strong disease resistance. Morphological and molecular biological techniques were used to determine its taxonomic status. A preliminary study was conducted on the control effect against AVC and the antifungal mechanism of the fungus and its fermentation broth. The results showed that the strain MG2, with the highest inhibitory rate(82.25%) against V. mali, was isolated from the bark tissue of Chaenomeles cathayensis. Based on the morphological observation and the comparison of multi-gene sequences, it was identified to be Chaetomium globosum. MG2 seemed to be more prone to inhibiting the mycelial growth of fungi from the Valsa genus, and it exhibited the most obvious inhibitory effect on V. mali. When V. mali was cultured against MG2, the mycelial growth became disorderly, and the mycelial morphology obviously changed. The MG2 showed excellent colonization capacity with no pathogenicity after being inoculated on the detached twigs of apple trees in advance, together with an optimal control effect for 72.46%. Additionally, the fermentation broth of MG2 showed an excellent inhibitory effect on the mycelial morphology and conidial germination of V. mali. After confrontation culture with MG2, expression levels of the genes associated with cell composition and metabolism in V. mali showed considerable changes. The cells could be stained with trypan blue, and the intracellular reducing sugar content significantly increased. To sum up, the Chaetomium globosum strain MG2, which has a high-efficiency biocontrol effect on V. mali, is an important microbial resource for the green management of AVC.更多还原