Stem rusts on wheat, barley, and oat in Canada in 1998

Abstract

Severities of the stem rusts of wheat and barley [Puccinia graminis f. sp. tritici] and oat [P. graminis f. sp. avenae] were light in Canada in 1998. Sixteen different pathotypes were identified from 151 P. g. tritici isolates, and 4 pathotypes were identified from 105 P. g. avenae isolates. The majority of P. g. tritici isolates from wheat were collected in Alberta and British Columbia, where the pathotype QFCSR made up 78% of the isolates. The majority of P. g. tritici isolates from barley were collected in Manitoba, where RCRSK made up 63% of the isolates. All P. g. tritici isolates were virulent to Sr5, Sr21, Sr9g, and Sr9d and avirulent to Sr22, Sr24, Sr25, Sr26, Sr27, Sr29, Sr30. Sr31, Sr32, Sr33, Sr37, and Sr40, a series of resistant lines, and commonly grown bread and durum wheat varieties. Most P. g. avenae isolates from both cultivated and wild oat were NA29. A pathotype new to western Canada, NA67, was identified that has combined virulence to Pgl3, Pg9, and Pg2. It constituted 15% of isolates from wild oat and 27% of isolates from cultivated oat and is virulent to the commonly grown oat cultivars in western Canada.

Keywords:

• Puccinia graminis
• physiological
• virulence