鸭粪中1株水稻纹枯病菌拮抗细菌的鉴定

为探索稻鸭复合生态系统抑制水稻纹枯病发生的作用机理,以从鸭粪中分离到的1株拮抗细菌A168对水稻纹枯病菌的拮抗效果进行了研究。测定了其对水稻纹枯病菌的拮抗作用及其抑菌谱;根据培养性状、形态特征、生理生化测定、扫描电镜观察及16S rDNA序列分析对其进行了鉴定;构建了包括其在内的13株相关种属菌株的系统发育树。A168菌株对水稻纹枯病有明显的拮抗作用,且对小麦赤霉病菌(Fusarium graminearum)、稻曲病菌(Ustilaginoidea virens)和油菜菌核病菌(Sclerotinia sclerotiorum)有抑制作用,抑菌谱广;A168菌体杆状,革兰氏染色阳性、芽孢中生、周生鞭毛、16S rDNA分析与其亲缘关系较近菌株Bacillus cereus(AJ577288.1)的同源性达99%,结合形态和生理生化特征,鉴定A168菌株为蜡状芽孢杆菌(Bacillus cereus),其16S rDNA序列已在GenBank中注册,登录号为GQ118339。A168为开发防治水稻纹枯病生防制剂提供了依据。

Identification of an antagonistic bacterial strain from duck manure against Rhizoctonia solani

The rice-duck system (raise duck in rice field) has resulted in the decrease of rice sheath blight caused by Rhizoctonia solani. The microbial flora from duck manure have been investigated and screened against R. solani. A168, a strain of antagonistic bacterium was obtained. The antagonism of A168 was evalu-ated toward fungal pathogens such as R. solani, Fusarium graminearum, Ustilaginoidea virens and Sclerotinia sclerotiorum. The bacterium was identified by culture characteristics, physiological and biochemical criteria, morphology and phylogenetic analysis of 16S rDNA sequences. The results showed that A168 had strong inhibition against R. solani, F. graminearum, U. virens and S. sclerotiorum. A168 was identified as Bacillus cereus and its characteristic were described. The 16S rDNA sequences of A168 had been registered at GenBank database under the accession number GQ118339.