菌株SYT-SF的筛选鉴定及生防效果验证

Screening and Identification of Strain SYT-SF and Its Biocontrol Effect Testing

为筛选拮抗烟草黑胫病病原烟草疫霉(Phytophthora parasitica var.nicotianae)的生防菌资源,本研究对连作烟田烟草黑胫病发病地块的健康烟株根际土壤中的细菌进行了分离培养、筛选,并对抑菌效果较好的菌株进行了鉴定及生防效果试验。结果表明:从根际土壤中共分离到35株菌,其中菌株SYT-SF对烟草疫霉的拮抗作用最强,抑菌率达到77.15%;菌株SYT-SF具有较好的抑菌广谱性;依据菌株SYT-SF的形态特征、生理生化特征、16S rDNA序列及gryA基因序列分析,将SYT-SF归属于假单胞菌属(Pseudomonas),暂定名为Pseudomonas sp.SYT-SF。盆栽试验表明,菌株SYT-SF预防组和治疗组对烟草黑胫病的生防效果分别达到71.97%和65.05%。菌株SYT-SF在烟草黑胫病生防菌剂及植烟土壤保育菌剂开发方面具有良好的应用潜力。

In order to screen the biocontrol bacteria resources against the pathogen Phytophthora parasitica var.nicotianae of tobacco black shank disease,this study isolated,cultured and screened the bacteria in the rhizosphere soil of healthy plants from the continuous cropping tobacco field affected by tobacco black shank disease.Then the strains with better antibacterial effects were identified,and their biocontrol effects were tested.The results showed that a total of 35 strains were isolated from the rhizosphere soil,of which,strain SYT-SF had the strongest antagonistic effect against P.parasitica var.nicotiana,with an inhibitory rate of 77.15%.The strain SYT-SF had good broad-spectrum antibacterial activity.According to the morphological characteristics,physiological and biochemical characteristics,16S rDNA sequence and gryA gene sequence analysis of strain SYT-SF,the SYT-SF was assigned to the genus Pseudomonas,tentatively named as Pseudomonas sp.SYT-SF.Pot experiment showed that the biocontrol effect of the strain SYT-SF against tobacco black shank disease in the prevention group and the treatment group reached 71.97%and 65.05%,respectively.The strain SYT-SF has a good application potential in the development of biocontrol agents and tobacco planting soil conservation agents for tobacco black shank disease.