Canadian Journal of Plant Pathology (2006) 28, 566-576

B.D. McCallum and P. Seto-Goh (2006)
Physiologic specialization of Puccinia triticina, the causal agent of wheat leaf rust, in Canada in 2004
Canadian Journal of Plant Pathology 28 (4), 566-576
Abstract: Virulence surveys are conducted annually in Canada on the pathogen causing leaf rust in wheat, Puccinia triticina, to monitor changes in the population and to quickly detect the development of virulence to important resistance genes in wheat. Forty-six virulence phenotypes were identified in 2004 from 330 P. triticina isolates, on the basis of their reactions to 16 wheat differential lines. There were 9 virulence phenotypes among 15 isolates from Quebec and 12 virulence phenotypes among 16 isolates from Ontario. There were 24 virulence phenotypes among 281 isolates from Manitoba and Saskatchewan, where the most frequently isolated were TBBJ (48.0%), TBBG (17.4%), and MBDS (10.0%). Each of the 3 isolates from Alberta possessed a unique virulence phenotype and there were five virulence phenotypes among 15 isolates from British Columbia. Only 3.9% of the isolates collected in 2004 were virulent to Lr16, which constituted a much lower percentage than in previous years. When a subset of 58 representative isolates was tested on adult plants, there were 47, 55, 0, 2, and 46 isolates virulent to the adult-plant resistance genes Lr12, Lr13, Lr34, Lr35, and Lr37, respectively. This subset of isolates varied for virulence on additional differentials tested at the seedling stage, with 30, 41, 18, 39, 26, 1, and 35 isolates virulent to Lr3bg, Lr14b, Lr15, Lr20, Lr23, Lr25, and Lr28, respectively.

À chaque année, des relevés de virulence de l'agent pathogène de la rouille des feuilles du blé, Puccinia triticina, sont effectués au Canada afin de surveiller les changements dans les populations et de détecter rapidement le développement de virulence envers d'importants gènes de résistance dans le blé. En 2004, 46 phénotypes de virulence furent identifiés parmi 330 isolats de P. triticina d'après leur comportement sur 16 lignées différentielles de blé. Il y avait 9 phénotypes de virulence parmi les 15 isolats du Québec et 12 phénotypes de virulence parmi les 16 isolats de l'Ontario. Il y avait 24 phénotypes de virulence parmi les 281 isolats du Manitoba et de la Saskatchewan, les plus fréquemment isolés étant TBBJ (48,0%), TBBG (17,4%) et MBDS (10,0%). Chacun des 3 isolats de l'Alberta possédait un phénotype de virulence unique et il y avait cinq phénotypes de virulence parmi les 15 isolats de la Colombie-Britannique. Seulement 3,9% des isolats obtenus en 2004 étaient virulents envers Lr16, ce qui constitute un pourcentage beaucoup moins élevé que ceux des années précédentes. Lorsqu'un sous-échantillon de 58 isolats représentatifs fut testé sur des plantes adultes, 47, 55, 0, 2 et 46 isolats, respectivement, furent virulents envers les gènes de résistance des plantes adultes Lr12, Lr13, Lr34, Lr35 et Lr37. La virulence de ce sous-échantillon d'isolats varia sur d'autres lignées différentielles testées au stade de semis, avec 30, 41, 18, 39, 26, 1 et 35 isolats virulents, respectivement, envers Lr3bg, Lr14b, Lr15, Lr20, Lr23, Lr25 et Lr28.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Brent D. McCallum

Research topic(s) for pests/diseases/weeds:
surveys/sampling/distribution
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Puccinia triticina	Wheat (Triticum)	Canada (east)
	Puccinia triticina	Wheat (Triticum)	Canada (west)