Articles
New sources of eastern filbert blight resistance in European hazelnut (Corylus avellana L.) mapped to linkage groups 2, 6, and 7
Article number
1379_11
Pages
73 – 80
Language
English
Abstract
Eastern filbert blight (EFB) disease caused by the fungal pathogen Anisogramma anomala (Peck) E. Müller is a major threat to Oregons hazelnut (Corylus avellana) industry.
The disease is also a main limiting factor to commercial hazelnut production in the eastern United States.
Host genetic resistance is the most economical and durable means to control the disease.
The Gasaway R gene, with a dominant allele at a single locus mapped to linkage group (LG) 6, provides a high level of resistance to EFB in Oregon.
The Oregon State University (OSU) hazelnut breeding program has incorporated Gasaway resistance in many commercial releases.
Cultivars with Gasaway resistance have been extensively planted throughout Oregons Willamette Valley over the past decade.
However, the long-term durability of this single source is a concern of the Oregon hazelnut industry.
An introduction event of one or more new virulent isolates to the Pacific Northwest or a mutation in the pathogen that enables it to overcome Gasaway resistance would have significant economic impacts.
Three genotypes (OSU 1168.098 from Sochi, Russia and Rutgers selections H3R07P07 and H3R12P58 from Crimea) have shown no EFB signs or symptoms following a series of greenhouse inoculations or exposures of potted trees under a structure topped with diseased wood.
All three resistance sources were crossed with susceptible selections to generate seedling populations.
The resulting seedlings were rated for disease on a scale from 0 to 5, with 0 having absence of disease symptoms and 5 having severe disease symptoms.
Ratings of 0-2 were considered resistant, and ratings of 3-5 were considered susceptible.
Segregation ratios indicated simple inheritance and good fit to a 1:1 segregation ratio.
Pearson correlation coefficients (r) between disease scores and allele scores at simple sequence repeat (SSR) marker loci were used to assign the resistance loci to linkage groups.
The SSR markers used in this study had been previously placed on the reference linkage map on LG 2, 6, or 7. Resistance from OSU 1168.098 from nuts purchased in a market in Sochi, Russia and Rutgers selections H3R07P07 and H3R12P58 from nuts purchased from different vendors in Crimea, was assigned to linkage groups 2, 6, and 7, respectively.
The results of this study will aid marker-assisted selection and the breeding of EFB-resistant cultivars with these new sources and facilitate the pyramiding of R genes in a single clonal selection for more durable resistance.
The disease is also a main limiting factor to commercial hazelnut production in the eastern United States.
Host genetic resistance is the most economical and durable means to control the disease.
The Gasaway R gene, with a dominant allele at a single locus mapped to linkage group (LG) 6, provides a high level of resistance to EFB in Oregon.
The Oregon State University (OSU) hazelnut breeding program has incorporated Gasaway resistance in many commercial releases.
Cultivars with Gasaway resistance have been extensively planted throughout Oregons Willamette Valley over the past decade.
However, the long-term durability of this single source is a concern of the Oregon hazelnut industry.
An introduction event of one or more new virulent isolates to the Pacific Northwest or a mutation in the pathogen that enables it to overcome Gasaway resistance would have significant economic impacts.
Three genotypes (OSU 1168.098 from Sochi, Russia and Rutgers selections H3R07P07 and H3R12P58 from Crimea) have shown no EFB signs or symptoms following a series of greenhouse inoculations or exposures of potted trees under a structure topped with diseased wood.
All three resistance sources were crossed with susceptible selections to generate seedling populations.
The resulting seedlings were rated for disease on a scale from 0 to 5, with 0 having absence of disease symptoms and 5 having severe disease symptoms.
Ratings of 0-2 were considered resistant, and ratings of 3-5 were considered susceptible.
Segregation ratios indicated simple inheritance and good fit to a 1:1 segregation ratio.
Pearson correlation coefficients (r) between disease scores and allele scores at simple sequence repeat (SSR) marker loci were used to assign the resistance loci to linkage groups.
The SSR markers used in this study had been previously placed on the reference linkage map on LG 2, 6, or 7. Resistance from OSU 1168.098 from nuts purchased in a market in Sochi, Russia and Rutgers selections H3R07P07 and H3R12P58 from nuts purchased from different vendors in Crimea, was assigned to linkage groups 2, 6, and 7, respectively.
The results of this study will aid marker-assisted selection and the breeding of EFB-resistant cultivars with these new sources and facilitate the pyramiding of R genes in a single clonal selection for more durable resistance.
Publication
Authors
R. Mooneyham, S.A. Mehlenbacher, D.C. Smith, J.W. Snelling
Keywords
Corylus avellana, hazelnut, disease resistance, Anisogramma anomala
Groups involved
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