title: Differentiation of Phytophthora infestans sporangia from other airborne biological particles by flow cytometry.
abstract: The ability of two different flow cytometers, the Microcyte (Optoflow) and the PAS-III (Partec), to differentiate sporangia of the late-blight pathogen Phytophthora infestans from other potential airborne particles was compared. With the PAS-III, light scatter and intrinsic fluorescence parameters could be used to differentiate sporangia from conidia of Alternaria or Botrytis spp., rust urediniospores, and pollen of grasses and plantain. Differentiation between P. infestans sporangia and powdery mildew conidia was not possible by these two methods but, when combined with analytical rules evolved by genetic programming methods, could be achieved after staining with the fluorescent brightener Calcofluor white M2R. The potential application of these techniques to the prediction of late-blight epiphytotics in the field is discussed.
authors.affiliation: Institute of Biological Sciences, University of Wales, Aberystwyth, Ceredigion, Wales SY23 3DA, United Kingdom.
authors.forename: Jennifer P
authors.initials: JP
authors.lastname: Day
authors.forename: Douglas B
authors.initials: DB
authors.lastname: Kell
authors.forename: Gareth W
authors.initials: GW
authors.lastname: Griffith
mesh_terms: D000391:Air Microbiology; D001557:Benzenesulfonates / Q000378:metabolism; D005434:Flow Cytometry / Q000295:instrumentation* / Q000379:methods*; D005456:Fluorescent Dyes / Q000378:metabolism; D008027:Light; D010316:Particle Size; D010838:Phytophthora / Q000145:classification* / Q000502:physiology*; D010935:Plant Diseases / Q000382:microbiology; D011058:Pollen; D012542:Scattering, Radiation; D011198:Solanum tuberosum / Q000382:microbiology; D013172:Spores, Fungal
chemical_list: D001557:Benzenesulfonates; D005456:Fluorescent Dyes; C007061:C.I. Fluorescent Brightening Agent 28