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ARS Home » Pacific West Area » Corvallis, Oregon » Forage Seed and Cereal Research Unit » Research » Publications at this Location » Publication #308228

Title: Characterization of resistance to powdery mildew in the Hop cultivars Newport and Comet

Author
item WOLFENBARGER, SIERRA - Oregon State University
item ECK, EMILY - Oregon State University
item Gent, David - Dave

Submitted to: Plant Health Progress
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/5/2014
Publication Date: 3/27/2014
Citation: Wolfenbarger, S.N., Eck, E.B., Gent, D.H. 2014. Characterization of resistance to powdery mildew in the Hop cultivars Newport and Comet. Plant Health Progress. DOI:10.1094/PHP-BR-13-0129.

Interpretive Summary: Hop powdery mildew is an important disease in the Northwestern U.S. Outbreaks of powdery mildew on cultivars previously resistant to the disease have been reported increasingly with the emergence of strains of the pathogen capable of overcoming a commonly deployed resistance gene. Studies were conducted to characterize powdery mildew resistance in two hop cultivars Newport and Comet frequently utilized in breeding programs. Powdery mildew resistance in both cultivars appears associated with a single resistance gene underlain with moderate to high levels of minor gene resistance. These cultivars may have value in breeding programs where low levels, but stable, resistance to powdery mildew is desired.

Technical Abstract: Hop powdery mildew, caused by Podosphaera macularis, is an important disease in the Northwestern U.S. Outbreaks of powdery mildew on cultivars previously resistant to the disease have been reported increasingly with the emergence of virulent pathogen strains capable of overcoming a commonly deployed resistance gene. Studies were conducted to characterize powdery mildew resistance in the cultivars Newport and Comet as these cultivars are frequently utilized in breeding programs, although the basis of their resistance to powdery mildew is unreported. Powdery mildew resistance in both cultivars appears associated with a single resistance gene underlain with moderate to high levels of quantitative resistance. These cultivars may have value in breeding programs where quantitative resistance to powdery mildew is desired.