中文摘要：

从印楝叶片和果实中分离93株内生放线菌。生长速率法测定表明29株内生放线菌对稻瘟病菌Magnaporthe grisea具有拮抗作用，其中菌株YL-2对稻瘟病菌的抑制率达82.65%。杯碟法测定表明菌株YL-2发酵液对供试的18种植物致病真菌均具有抑菌活性，盆栽试验表明菌株YL-2发酵液对稻瘟病防效达85.41%，显著高于浓度为25 mg/L春雷霉素可湿性粉剂的防效。根据形态特征、生理生化特性、细胞壁化学成分和16S rDNA序列，初步鉴定菌株YL-2为娄彻氏链霉菌Streptomyces rochei。

英文摘要：

Ninety-three endophytic actinomycetes were isolated from the leaf and fruit of Azadirachta indica A. Juss.. The results showed that 29 strains had antagonistic activities against Magnaporthe griseaby measuring mycelial growth rate method. The strain YL-2 had a strong antifungal activity againstM. grisea with the inhibition rate of 82.65%. And it exhibited antagonistic activities against 18 kinds of plant pathogenic fungi by cylinder-plate method. The pot experiment showed that the control efficiency of filtrate from YL-2 fermentation liquid onM. griseawas significantly higher than 25 mg/L Kasugamycin WP which could be up to 85.41%. According to the morphological characteristics, physiological and biochemical properties, chemical composition of the cell wall and 16S rDNA, the strain YL-2 was preliminarily identified asStreptomyces rochei.