ARS | Publication request: Characterization of a basidiomycete fungus from sugarbeet in Idaho

Submitted to: Inoculum
Publication Type: Abstract
Publication Acceptance Date: June 2, 2008
Publication Date: July 31, 2008
Citation: Toda, T., Strausbaugh, C.A., Vilgalys, R., Cubeta, M.A. 2008. Characterization of a basidiomycete fungus from sugarbeet in Idaho. Inoculum. 59:59.

Technical Abstract: A fungus of unknown etiology was observed on stored sugarbeet roots exhibiting signs of white cottony growth in 2006 and 2007 in Idaho. Eighteen isolates obtained from sugarbeet roots were examined for growth characteristics on nutrient medium, production of phenol oxidases and ITS rDNA sequence. On malt extract (MEA) and potato dextrose (PDA) agar, each isolate produced white colored mycelium with a mean radial growth rate of 1 to 4 mm per day at temperatures ranging from 3 to 22 C. The optimum temperature for mycelial growth was 12-16 C with no growth occurring at 30 C. The isolates produced sclerotial-like structures after 6 days of incubation on MEA and PDA that formed in concentric rings and became orange in color after 2 wk. All isolates had hyaline, septate hyphae with clamp connections and two nuclei per hyphal cell, but did not produce asexual or sexual spores. On MEA and PDA amended with 0.5% tannic acid, all isolates produced a green, orange, and red color after applying solutions of gum guiac, guiacol, and syringaldezine, respectively, suggesting that they produced phenol oxidases. Sequences of the rDNA-ITS region in all isolates were nearly identical and 98 % similar to a sequence deposited in GenBank (accession no. AY969953) from an uncultured basidiomycete. Research is currently in progress to better characterize and identify this basidiomycete fungus.