title: Selection of antagonistic bacteria isolated from the Physalis peruviana rhizosphere against Fusarium oxysporum.
abstract: OBJECTIVE
  Cape gooseberries (Physalis peruviana) have become increasingly important in Colombia for both domestic consumption and the international export market. Vascular wilting caused by Fusarium oxysporum is the most damaging disease to P. peruviana crops in Colombia. The control of this pathogen is mainly carried out by chemical and cultural practices, increasing production costs and generating resistance. Therefore, the objectives of this study were to test rhizobacteria isolates from P. peruviana rhizosphere against F. oxysporum under in vitro and in vivo conditions.
  
  
  RESULTS
  Over 120 strains were isolated, and five were selected for their high inhibition of F. oxysporum growth and conidia production under in vitro conditions. These strains inhibited growth by 41-58% and reduced three- to fivefold conidia production. In the in vivo assays, all the tested isolates significantly reduced fungal pathogenicity in terms of virulence. Isolate B-3.4 was the most efficient in delaying the onset of the first symptoms. All isolates were identified as belonging to the genus Pseudomonas except for A-19 (Bacillus sp.).
  
  
  CONCLUSIONS
  Our results confirmed that there are prospective rhizobacteria strains that can be used as biological control agents; some of them being able to inhibit in vitro F. oxysporum growth and sporulation.
  
  
  CONCLUSIONS
  Incorporating these bacteria into biological control strategies for the disease that causes high economical losses in the second most exported fruit from Colombia would result in a reduced impact on environment and economy.
authors.affiliation: Laboratorio de Fitopatología, Facultad de Ciencias, Universidad Militar Nueva Granada, Bogotá, DC, Colombia.
authors.forename: R
authors.initials: R
authors.lastname: Urrea
authors.forename: L
authors.initials: L
authors.lastname: Cabezas
authors.forename: R
authors.initials: R
authors.lastname: Sierra
authors.forename: M
authors.initials: M
authors.lastname: Cárdenas
authors.forename: S
authors.initials: S
authors.lastname: Restrepo
authors.forename: P
authors.initials: P
authors.lastname: Jiménez
mesh_terms: D000898:Antibiosis; D001407:Bacillus / Q000302:isolation & purification / Q000502:physiology; D061046:Biological Control Agents; D003105:Colombia; D005670:Fusarium / Q000254:growth & development / Q000472:pathogenicity*; D032321:Physalis / Q000382:microbiology*; D010935:Plant Diseases / Q000382:microbiology / Q000517:prevention & control; D011549:Pseudomonas / Q000302:isolation & purification / Q000502:physiology*; D058441:Rhizosphere; D013172:Spores, Fungal / Q000254:growth & development / Q000472:pathogenicity; D014774:Virulence
chemical_list: D061046:Biological Control Agents