title: In vitro analyses are not reliable predictors of the plant growth promotion capability of bacteria; a Pseudomonas fluorescens strain that promotes the growth and yield of wheat.
abstract: OBJECTIVE
  In this study, we set out to identify bacteria that can be used to promote the growth of cereals, while concurrently investigating the merits of using a range of such tests to preselect bacteria for glasshouse studies.
  
  
  RESULTS
  A panel of 15 strains isolated from the rhizosphere and phyllosphere of cereals was tested for the ability to improve the germination of wheat seeds and for production of a range of factors associated with plant growth promotion. In parallel, all bacteria were tested for their ability to improve biomass and grain yield when applied as a soil amendment in glasshouse trials.
  
  
  CONCLUSIONS
  There was no significant correlation between growth promotion potential in the glasshouse and the results of either the phenotypic or the germination tests. Glasshouse tests identified that only one strain, Pseudomonas fluorescens strain MKB37, gave a significant increase in head weight and grain yield.
  
  
  CONCLUSIONS
  While this study has identified a candidate for further field tests, it has also highlighted the fact that the modes of action for plant growth-promoting bacteria (PGPB) are still not fully understood, and that there is no efficient and effective screening method for identifying PGPB by laboratory tests.
authors.affiliation: School of Biology and Environmental Science, University College Dublin, Belfield, Dublin, Ireland. eoghan.smyth@ucd.ie
authors.forename: E M
authors.initials: EM
authors.lastname: Smyth
authors.forename: J
authors.initials: J
authors.lastname: McCarthy
authors.forename: R
authors.initials: R
authors.lastname: Nevin
authors.forename: M R
authors.initials: MR
authors.lastname: Khan
authors.forename: J M
authors.initials: JM
authors.lastname: Dow
authors.forename: F
authors.initials: F
authors.lastname: O'Gara
authors.forename: F M
authors.initials: FM
authors.lastname: Doohan
mesh_terms: D018533:Biomass; D004269:DNA, Bacterial / Q000235:genetics; D018525:Germination; D011551:Pseudomonas fluorescens / Q000235:genetics / Q000502:physiology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D058441:Rhizosphere; D012639:Seeds / Q000254:growth & development* / Q000382:microbiology; D012988:Soil Microbiology; D014908:Triticum / Q000254:growth & development* / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S