Wheat powdery mildew caused by Blumeria graminis f. sp. tritici (Bgt) is one of the most serious wheat diseases in the world. Biological control is considered an environmentally safe approach to control plant diseases. Here, to develop effective biocontrol agents for controlling wheat powdery mildew, antagonistic strain XZ16-1 was isolated and identified as Bacillus subtilis based on the morphological, biochemical, and physiological characteristics and 16S rDNA sequence. The culture filtrate of B. subtilis XZ16-1 and its extracts had a significant inhibitory effect on the spore germination of Bgt. Moreover, the therapeutic and prevention efficacy of the 100% culture filtrate on wheat powdery mildew reached 81.18 and 83.72%, respectively, which was better than that of chemical fungicide triadimefon. Further antimicrobial mechanism analysis showed that the XZ16-1 culture filtrate could inhibit the development of powdery mildew spores by disrupting the cell membrane integrity, causing reductions in the mitochondrial membrane potential, and inducing the accumulation of reactive oxygen species in the spores. Biochemical detection indicated that XZ16-1 could solubilize phosphate, fix nitrogen, and produce hydrolases, lipopeptides, siderophores, and indole-3-acetic acid. Defense-related enzymes activated in wheat seedlings treated with the culture filtrate indicated that disease resistance was induced in wheat to resist pathogens. Furthermore, a 10⁶ CFU/ml suspension of XZ16-1 increased the height, root length, fresh weight, and dry weight of wheat seedlings by 77.13, 63.46, 76.73, and 19.16%, respectively, and showed good growth-promotion properties. This study investigates the antagonistic activity and reveals the action mechanism of XZ16-1, which can provide an effective microbial agent for controlling wheat powdery mildew.

由Blumeria graminis f.引起的小麦白粉病。sp。小麦病害( Bgt ) 是世界上最严重的小麦病害之一。生物控制被认为是一种控制植物病害的环境安全方法。为开发有效防治小麦白粉病的生防剂，本研究分离出拮抗菌株XZ16-1，根据形态学、生化和生理特征及16S rDNA序列鉴定为枯草芽孢杆菌。枯草芽孢杆菌XZ16-1培养滤液及其提取物对Bgt孢子萌发有明显抑制作用. 100%培养滤液对小麦白粉病的防治效果分别达到81.18%和83.72%，优于化学杀菌剂三唑酮。进一步的抗菌机制分析表明，XZ16-1培养滤液可通过破坏细胞膜完整性、降低线粒体膜电位和诱导孢子中活性氧的积累来抑制白粉病孢子的发育。生化检测表明，XZ16-1具有溶磷、固氮、水解酶、脂肽、铁载体和吲哚-3-乙酸等活性。在用培养滤液处理的小麦幼苗中激活的防御相关酶表明在小麦中诱导了抗病性以抵抗病原体。此外，⁶ CFU/ml的XZ16-1悬浮液使小麦幼苗的株高、根长、鲜重和干重分别增加77.13%、63.46%、76.73%和19.16%，表现出良好的促生性能。本研究考察了XZ16-1的拮抗活性并揭示了其作用机制，可为防治小麦白粉病提供一种有效的微生物菌剂。