title: Endophytic Bacillus subtilis strain E1R-J is a promising biocontrol agent for wheat powdery mildew.
abstract: In this study, the biocontrol efficacies of 14 endophytic bacterial strains were tested against Blumeria graminis f. sp. tritici (Bgt) in pot experiments under greenhouse conditions. Bacillus subtilis strain E1R-j significantly reduced disease index and exhibited the best control (90.97%). When different formulations of E1R-j were sprayed 24 h before Bgt inoculation, fermentation liquid without bacterial cell and crude protein suspension displayed the similar effects; and they reduced disease index more than bacterial cell suspension (10(9) cfu mL(-1)) and fermentation liquid without protein. The control effects were not significantly different between 10(11) and 10(9) cfu mL(-1) of bacterial cell suspension but were higher than 10(7) cfu mL(-1). Further observations showed that conidial germination and appressorial formation of Bgt were retarded by spraying E1R-j 24 h before Bgt inoculation. Compared with the water check, conidial germination and appressorial formation were decreased by 43.3% and 42.7%, respectively. In the treatment with E1R-j, the number of houstoria significantly reduced and the speed of mycelial extension was slowed down in the wheat leaves. Scanning electron microscopy observation revealed that E1R-j significantly suppressed the conidial germination and caused rupture and deformation of germ tubes. On the surface of wheat leaves, mycelia and conidiophores became shrinking.
authors.affiliation: College of Plant Protection and State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Xiaoning
authors.identifier: 0000-0002-3584-134X
authors.initials: X
authors.lastname: Gao
authors.affiliation: College of Plant Protection and State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Yufei
authors.initials: Y
authors.lastname: Gong
authors.affiliation: College of Plant Protection and State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Yunxia
authors.initials: Y
authors.lastname: Huo
authors.affiliation: College of Plant Protection and State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Qingmei
authors.initials: Q
authors.lastname: Han
authors.affiliation: College of Plant Protection and State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Zhensheng
authors.initials: Z
authors.lastname: Kang
authors.affiliation: College of Plant Protection and State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Huang
mesh_terms: D001203:Ascomycota / Q000254:growth & development; D001412:Bacillus subtilis / Q000502:physiology*; D018525:Germination / Q000502:physiology; D025282:Mycelium / Q000502:physiology; D010935:Plant Diseases / Q000382:microbiology*; D018515:Plant Leaves / Q000382:microbiology; D014908:Triticum / Q000382:microbiology*