Identifying Wheat Genotypes Resistant to Eyespot Disease with abeta-Glucuronidase-Transformed Strain ofPseudocercosporella herpotrichoides

Resistance to Pseudocercosporella herpotrichoides in wheat was determined by inoculating 2-wk-old seedlings with a transformed strain of the pathogen that constitutively expresses β-glucuronidase (GUS) and measuring disease development with a GUS enzyme assay, visual disease scoring, and an enzyme-linked immunosorbent assay (ELISA). Differences among resistant and susceptible genotypes were apparent 2 wk after inoculation; however, the greatest differences among resistant and susceptible genotypes occurred 4- to 6-wk and 6- to 8-wk after inoculation for the GUS assay and visual disease ratings, respectively. ELISA did not differentiate among resistant genotypes at any sample date in this study