Fluorescent staining of resting spores of Polymyxa betae as a fungal vector of rhizomania disease of sugar beet in soil

When the resting spores of Polymyxa betae were pretreated with 2% sodium dodecyl sulfate (SDS) and then stained with various fluorochromes including 3,3′-dihexyloxacarbocyanine iodide [DiOC6(3)], calcofluor, and a fluorescein isothiocyanate (FITC)-conjugated lectin, such as wheat germ lectin (WGA) or caster bean lectin, most spores fluoresced brightly. FITC-WGA mainly stained the cell surface, while DiOC6(3) stained the cytoplasm. After pretreatment with SDS and addition of FITC-WGA or DiOC6(3) to a soil suspension containing resting spores, the resting spores were distinguishable from the soil particles. This staining method is easy to use for the detection of resting spores in the soil. © The Phytopathological Society of Japan and Springer-Verlag 2006.