A Note on the Identification of Virulence Factors in the Wheat Powdery Mildew (Erysiphe graminis f. sp. Tritici) Population in Co. Cork in 1995

A total of 19 wheat powdery mildew isolates were obtained from glasshouse and field sites in Co. Cork. The virulence factors present in these isolates were identified by inoculating 13 differential wheat varieties (containing known powdery mildew resistance genes) with each isolate. Ten virulence factors were identified: 2, 4b, 5, 6, 8, d, Ta2, 3d, To and Ax. Four distinct pathotypes were identified. The most common pathotype was the same as in the UK in 1995, and the frequencies of the 10 virulence factors identified were positively correlated with the corresponding values in the UK Survey.