杨树烂皮病内生拮抗菌的筛选及鉴定

从健康杨树枝条上分离到1株能有效抑制杨树烂皮病菌的内生细菌,编号为NS3。该菌株对供试的13种植物病原菌均有抑制作用,抑菌谱广,其中对杨树烂皮病和杨树溃疡病病原菌抑制作用最强,其活菌的平均抑菌带宽度达到25.6mm以上,发酵液的抑菌圈直径达到48.6mm以上;人工接种防治试验结果表明:发酵液的无菌滤液对杨树烂皮病具有良好的生防作用,保护作用和治疗作用分别达85.4%和69.6%,与生产上用于防治该病的常用药剂防治效果差异不显著;根据其菌株形态、生理生化特征和16SrDNA序列比对,最终将该菌株鉴定为枯草芽胞杆菌(Bacillus subtilis)。

Screening of antagonistic bacteria of Valsa sordida and identification of the strain NS3

An antagonistic bacterial strain NS3 against Vasal sordida was isolated from poplar branches. The NS3 strain displayed a broad spectrum inhibition to all the 13 pathogenic fungi tested in this study. Of them, its inhibitive effect to Vasal sordida and Botryosphaeria dothidea was the strongest, with a width of inhibition zone of more than 25.6 mm and a diameter of 48.6 mm averagely for NS3 fermented broth. Meanwhile, the inoculation test suggested its great potential for biocontrol. The protection and curation of the fermented broth against V.sordida were raised to 85.4% and 69.6%, respectively. On the basis of the morphological and physiological biochemical characteristics as well as 16S rDNA sequence analysis, the bacterium was identified as Bacillus subtilis.