Race characterization of Pyrenophora tritici-repentis and sensitivity to propiconazole and pyraclostrobin fungicides. Issue 4 (2nd October 2017)

• Record Type: Journal Article
• Authors: MacLean, Dustin E.; Aboukhaddour, Reem; Tran, Van Anh; Askarian, Homa; Strelkov, Stephen E.; Turkington, T. Kelly; Kutcher, Hadley R.
• Is Part Of: Canadian journal of plant pathology. Volume 39:Issue 4(2017)
• Page Start: 433
• Page End: 443
• Publication Date: 2017-10-02
• Subjects: fungicide -- race characterization -- sensitivity -- tan spot -- wheat; blé -- caractérisation de la race -- fongicide -- sensibilité -- tache helminthosporienne; Plant diseases -- Canada -- Periodicals; Plant diseases -- Periodicals; 632.05
• DOI: 10.1080/07060661.2017.1387178
• Languages: English
• ISSNs: 0706-0661

Abstract

Abstract: Tan spot, caused by Pyrenophora tritici-repentis ( Ptr ), is one of the most destructive leaf spot diseases of wheat in Canada. Several races of the fungus are known to occur. Wheat growers have adopted fungicides to manage tan spot; however, intensive spraying may lead to development of reduced sensitivity to fungicides in the pathogen. In this study, 62 Ptr isolates were collected from across Saskatchewan and Alberta and characterized to race on a wheat differential set, with confirmation of race designations by polymerase chain reaction. This same set of isolates, and 27 isolates from an earlier study, were also evaluated for sensitivity to propiconazole and pyraclostrobin fungicides by determining the effective concentration of each needed to inhibit radial growth and conidiospore germination by 50%. Races 1 and 2 were predominant in western Canada, with 57% of isolates classified as race 1 and 40% as race 2. In Alberta, race 1 was most common (76%), while in Saskatchewan, it was race 2 (57%). Two of 26 isolates were classified as race 3, which was detected only in Saskatchewan in 2013. There was no evidence of reduced sensitivity of either fungicide in the Ptr isolates examined. This study provides a baseline for Ptr sensitivity to propiconazole and pyraclostrobin to which future collections of the pathogen may be compared.