烟草疫霉生防细菌的筛选及鉴定

Screening and Identification of a Bacterium Antagonistic to Phytophthora parasitica var. nicotianae

为获得防治烟草黑胫病的生防菌株,通过对峙平板法,从烟田土壤中分离出1株对烟草疫霉具有很好抑菌作用的细菌B40-3。培养3 d后,该菌株对烟草疫霉抑菌带宽度为0.9 cm,抑菌圈半径为2.3 cm,并对其余12种植物病原真菌有很好抑制作用。该菌株在LB液体培养基中,37℃,210 rpm条件下培养40 h,OD值达到最大值。依传统生理生化反应鉴定,B40-3属于枯草芽孢杆菌。

A biocontrol bacterial strain B40-3 antagonistic to Phytophthora parasitica var. nicotianae, a pathogen of tobacco black shrank, was isolated from tobacco-growing field by dual culture. The isolate had 0.9 cm ftmgistasis band and 2.3 cm inhibitory radius when it co-cultured with the pathogen for 3 days. B40-3 could inhibit other 13 fungal pathogens as well. In LB broth medium, its OD600 value reached to the maximum at 37 ~C, 210 rpm for 40 hours. B40-3 was identified as Bacillus subtilis by the traditional spore staining and physiological and biochemical reactions,