防治烟草根黑腐病拮抗芽孢菌株的筛选

Screening of antagonistic Bacillus spp.against Thielaviopsis basicola

由基生根串珠霉菌（Thielaviopsis basicola）引起的烟草根黑腐病是烟草生产上重要根部真菌病害,近年在我国烟草种植区有加重危害的趋势,目前防治措施主要依赖化学药剂,给卷烟卫生带来一系列问题。探索该病生物防治途径,克服农药残留和病原菌抗药性十分重要。芽孢杆菌是土壤和植物微生态区系的优势生物种群,具有优良生防特性,采用芽孢杆菌作为烟草根黑腐病生防因子尚未见报道。本研究从烟草根际土壤中分离筛选对烟草根黑腐病病菌有较强拮抗作用的芽孢菌株,研究其抑菌活性、控病作用及其分类学地位。

Among 265 bacterial isolates obtained from tobacco rhizosphere collected from Chongqing,5 bacillus strains were showed high antagonistic effect against Thielaviopsis basicola,the pathogen of tobacco black root rot.The inhibition zone diameters were ranged from 7.0-10.5 mm by pairing culture on PDA plates.Strain R27 effectively reduced the incidence of tobacco black root rot,and the control efficacy reached 80.2% in greenhouse experiment.The culture filtrate of strain R27 could inhibit hyphal growth and reduce spore germination of T.basicola.According to the characteristics of morphology,physiology and biochemistry,and analysis of its 16S rDNA sequence,strain R27 was identified as Bacillus subtilis.