Pathogenic variation in Rhynchosporium secalis on barley in New Zealand

Abstract

Four races of Rhynchosporium secalis were identified from 149 New Zealand isolates on the basis of their virulence on a set of 7 New Zealand barley cultivars and 11 differentials used in studies in Europe, North America, and Australia. The most common race, accounting for 59% of all isolates and 84% of isolates from susceptible cultivars, was virulent only on the universal suscept, ‘Triumph’. No isolates were virulent on more than one other differential and most differentials were resistant to all isolates. Differences in virulence patterns of New Zealand isolates compared with those from other countries were apparent.

Keywords:

• barley
• Hordeum vulgare
• scald
• pathogenic races