草鱼肠道细菌CD-17的鉴定和生防活性研究
Biocontrol Activity and Taxonomy of Grass Carp Intestine Bacteria CD-17

为筛选新的生防菌种，采用平板对峙培养法测定分离自草鱼肠道细菌CD-17菌株对常见植物病原真菌的抑菌谱。通过菌株形态学扫描电镜观察、平板培养生理生化特性和分子辅助分类法确定其分类地位，同时对其活菌制剂（BCA）进行温室防效试验。结果表明，CD-17对供试植物病原真菌均有不同程度的抑制作用；温室控制条件下，BCA与炭疽病菌分生胞子悬浮液（GC）同时接种正常草莓叶片和接种GC 48 h后再用BCA的控制效果分别为100%和55.68%；BCA与GC同时接种有微伤口的草莓叶片和接种GC 48 h后再用BCA的控制效果分别仅为76.94%和37.82%。根据菌株形态观察、生理生化特征、16Sr DNA 基因和gyrB基因序列比对分析，鉴定该菌株为解淀粉芽胞杆菌（Bacillus amyloliquefaciens）。
To discover new biological control agents, the biocontrol activity of grass carp intestine bacteria strain CD-17 was interpreted by dual-cultural plate method and greenhouse effect test of CD-17 biocontrol agent (BCA).Based on the morphological, chemical and molecular taxonomy methods, the strain CD-17 was identified.The results showed that the strain CD-17 displayed a broad-spectrum inhibitive activity.Data from greenhouse experiments under the control condition revealed the control efficacy of BCA and spores suspension of strawberry anthracnose (GC) inoculated at the same time and BCA spray after 48 h inoculation with GC on the normal strawberry leaf were 100% and 55.68%, respectively.However, the control efficacy of BCA and GC inoculated at the same time and BCA sprayed after 48 h inoculation with GC on the slight wound strawberry leaf were only 76.94% and 37.82%,respectively.According to the morphological, physiological, biochemical characteristics, 16S rDNA and gyrB gene sequence, the strain CD-17 was identified as Bacillus amyloliquefaciens.