中文摘要：

为筛选对草莓根腐尖孢镰刀菌（Fusarium oxysporum）有较好抑菌活性的草莓内生细菌，从草莓的根、茎、叶和果实中分离内生细菌，采用平板对峙法筛选具有抑菌活性的菌株，经形态特征观察、生理生化特性及分子鉴定后，进行拮抗菌抑菌特性分析．结果筛选到1株对草莓根腐尖孢镰刀菌具有较高抑菌活性（抑菌带达9．8mm）、稳定性较好的菌，标记为SY-4．此外，该菌对桃褐腐病菌（Monilinia）Cruticola）、棉花红腐病菌（Fusat-iummoniliforme）和草莓根腐石楠拟盘多毛孢（Pestalotiopsis photiniae）等也有较好的拮抗作用．SY_4经鉴定确定为枯草芽胞杆菌．SY-4发酵液在培养时间48h、培养温度37℃、pH值为7时，抗菌效果最好，但发酵产物不耐高温、不耐酸、较耐碱性，对蛋白酶敏感，初步说明存在蛋白类抑菌活性物质．电镜观察发现SY-4发酵液处理草莓根腐尖孢镰刀菌后，菌丝形态变得不规则．该拈抗内生细菌是潜在的植物病原真菌生防菌资源，具有一定的开发与应用价值．图4表2参16

英文摘要：

The aim of this study was to isolate endophytic antagonistic bacteria from strawberry. Endophytic bacteria strains were isolated from strawberry roots, stems, leaves and fruit. The inhibitory activities of these bacteria against strawberry root rot （Fusarium oxysporum） were tested using five-point confrontation method. The characters of antagonistic metabolites of endophytic antagonistic bacteria were also preliminarily studied. One out of 36 isolates was found to have high inhibitory activities against F. oxysporum with inhibition zone of 9.8 mm. The strain was named SY-4. In addition, the strain SY-4 also had high antagonistic effects on Moniliniafvuticola, Fusarium moniliforme and Pestalotiopsis photiniae. According to its mophological, physiological and biochemical characteristics as well as 16S rRNA sequences, SY-4 was identified as Bacillus subtilis. B. subtilis SY-4 showed best antifungal activities at the culture time of post-48 h, pH of 7, and temperature of 37 ~（＇. Furthermore, the antagonistic activities of B. subtilis SY-4 were significantly affected by treatment of high temperature, or strong acid condition, or with trypsin and proteinase k, suggesting that the strain SY-4 contained protein antifungal metabolites. Its metabolic products treatment could lead to fungal mycelium abnormality, condensed bioplasm and increased cellular vacuole observed by transmission electron microscopy. The strain SY-4 is an potent antagonistic bacteria source with good application future.