title: [Screening, identification, and antagonism assessment, of dominant bacteria in Ageratina adenophora Sprengel rhizosphere soil].
abstract: By using isolation and culture method, 25 strains of dominant bacteria in Ageratina adenophora rhizosphere soil were isolated and identified, of which, 8 strains were assessed for their antagonistic activity. The results showed that Bacillus and Pseudomonas were highly abundant in A. adenophora rhizosphere soil, of which, B. subtilis and B. megaterium were most abundant and occupied 55.6% of the total identified bacteria. These dominant bacteria had different level antagonistic activity to Fusarium oxysporum and Ralstonia solanacearum, and B. subtilis BS-5 and B. thuringiensis BT-1 had the strongest antagonistic effect on F. oxysporum, with the antagonistic activity of their metabolic products being 85.5% and 83.8%, respectively. The metabolic products of the dominant antagonistic bacteria had even more stronger antagonistic effect on pathogens than the dominant antagonistic bacteria themselves. The existence of abundant bacterial groups with strong antagonistic activity in A. adenophora rhizosphere soil could help A. adenophora to resist harmful soil-borne diseases and escape its natural enemies. Through the feedback actions of the beneficial rhizosphere microbes, A. adenophora probably earned its competition superiority directly or indirectly, being favorable to its rapid expansion.
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Hongbangniu@hotmail.com
authors.forename: Hong-Bang
authors.initials: HB
authors.lastname: Niu
authors.forename: Wan-Xue
authors.initials: WX
authors.lastname: Liu
authors.forename: Fang-Hao
authors.initials: FH
authors.lastname: Wan
authors.forename: Bo
authors.initials: B
authors.lastname: Liu
mesh_terms: D036603:Ageratina / Q000254:growth & development / Q000382:microbiology*; D000898:Antibiosis / Q000502:physiology*; D001410:Bacillus megaterium / Q000302:isolation & purification / Q000502:physiology; D001412:Bacillus subtilis / Q000302:isolation & purification / Q000502:physiology; D005670:Fusarium / Q000302:isolation & purification / Q000502:physiology; D018517:Plant Roots / Q000382:microbiology*; D011549:Pseudomonas / Q000302:isolation & purification / Q000502:physiology; D012988:Soil Microbiology