Validation of species-specific diagnostic tests for five Rhynchosporium species.

All the diagnostic tests detected only the predicted Rhynchosporium species when tested against a range of fungal isolates and plant DNA. PCR using primer pair LinA-F/R produced an amplicon of 145-bp specific for R. commune isolates; RA6-F/R produced an amplicon of 461-bp specific for R. agropyri isolates; RS25-F/R produced an amplicon of 1240-bp specific for R. secalis isolates; 2RO-F/R produced an amplicon of 277-bp specific for both R. orthosporum and R. lolii isolates; rep-PCR genomic fingerprinting using primers ERIC2/BOXA1R produced an amplicon of ∼400-bp specific for isolates of R. lolii.aBarley (cv. Sumo), rye or cocksfoot DNA extracted from leaves of healthy seedlings (no leaf blotch lesions present) grown under controlled environment conditions was confirmed to be free of detectable Rhynchosporium DNA using the quantitative PCR assay of Fountaine et al. [30] (data not shown);bn/a = not applicable.