Articles
GENETIC RESOURCES FOR HAZELNUT: STATE OF THE ART AND FUTURE PERSPECTIVES
Article number
845_1
Pages
33 – 38
Language
English
Abstract
World production of the European hazelnut (Corylus avellana L.) is based primarily on selections from the wild.
Breeding programs are developing new cultivars for the kernel and in-shell markets, but efforts are limited.
To date, the hazelnut breeding program at Oregon State University has released six cultivars, eight pollinizers, and two ornamentals.
Micropropagation allows routine, rapid multiplication of new cultivars. C. avellana is highly polymorphic, and cultivars have been collected and preserved in several genebanks.
Collections in Corvallis house more than 900 accessions of Corylus, of which 500 are C. avellana. Recent introductions include germplasm from Turkey and the former Soviet Union.
Of more than 500 known cultivars, only about 20 are worthy of consideration for commercial production.
Apple mosaic virus is common in cultivars from some regions, but infected trees often show no symptoms.
Very strict plant quarantine regulations designed to prevent the spread of eastern filbert blight, caused by Anisogramma anomala, also prevent the sharing of improved cultivars.
Genetic studies have identified several simply inherited traits.
Most economically important traits are quantitative with moderate to high heritabilities.
Climatic adaptation is rarely a concern in the major production areas, but expansion of hazelnut plantings into marginal areas will require the development of adapted cultivars from diverse germplasm and identification of suitable pollinizers.
Genetic diversity in other species will be useful in breeding efforts for marginal areas.
Studies at the DNA level have been useful in clarifying the taxonomy of Corylus and related genera.
More than 150 microsatellite markers have been developed and placed on the linkage map where they serve as anchor loci, and many also amplify Betula. Characterization with microsatellite markers showed that 72 of 270 accessions in the Corvallis collections were duplicates, and assigned most accessions to one of four major geographic groups: Central European, Black Sea, English and Spanish-Italian.
Eastern filbert blight is a major concern in North America.
Several sources with high levels of resistance have been identified and are being used in breeding, with selection facilitated by DNA markers.
A bacterial artificial chromosome (BAC) library will allow map-based cloning of important genes, including eastern filbert blight resistance from Gasaway and the S-locus that controls pollen-stigma incompatibility.
Public databases now include very few Corylus sequences.
EST sequences from other genera and species in the order Fagales may be useful for studies in Corylus, as synteny of the genomes is expected.
Hazelnut is amenable to Agrobacterium-mediated transformation, with regeneration most successful if explants are from germinating seeds or very young seedlings.
Breeding programs are developing new cultivars for the kernel and in-shell markets, but efforts are limited.
To date, the hazelnut breeding program at Oregon State University has released six cultivars, eight pollinizers, and two ornamentals.
Micropropagation allows routine, rapid multiplication of new cultivars. C. avellana is highly polymorphic, and cultivars have been collected and preserved in several genebanks.
Collections in Corvallis house more than 900 accessions of Corylus, of which 500 are C. avellana. Recent introductions include germplasm from Turkey and the former Soviet Union.
Of more than 500 known cultivars, only about 20 are worthy of consideration for commercial production.
Apple mosaic virus is common in cultivars from some regions, but infected trees often show no symptoms.
Very strict plant quarantine regulations designed to prevent the spread of eastern filbert blight, caused by Anisogramma anomala, also prevent the sharing of improved cultivars.
Genetic studies have identified several simply inherited traits.
Most economically important traits are quantitative with moderate to high heritabilities.
Climatic adaptation is rarely a concern in the major production areas, but expansion of hazelnut plantings into marginal areas will require the development of adapted cultivars from diverse germplasm and identification of suitable pollinizers.
Genetic diversity in other species will be useful in breeding efforts for marginal areas.
Studies at the DNA level have been useful in clarifying the taxonomy of Corylus and related genera.
More than 150 microsatellite markers have been developed and placed on the linkage map where they serve as anchor loci, and many also amplify Betula. Characterization with microsatellite markers showed that 72 of 270 accessions in the Corvallis collections were duplicates, and assigned most accessions to one of four major geographic groups: Central European, Black Sea, English and Spanish-Italian.
Eastern filbert blight is a major concern in North America.
Several sources with high levels of resistance have been identified and are being used in breeding, with selection facilitated by DNA markers.
A bacterial artificial chromosome (BAC) library will allow map-based cloning of important genes, including eastern filbert blight resistance from Gasaway and the S-locus that controls pollen-stigma incompatibility.
Public databases now include very few Corylus sequences.
EST sequences from other genera and species in the order Fagales may be useful for studies in Corylus, as synteny of the genomes is expected.
Hazelnut is amenable to Agrobacterium-mediated transformation, with regeneration most successful if explants are from germinating seeds or very young seedlings.
Publication
Authors
S.A. Mehlenbacher
Keywords
Corylus, filbert, breeding, germplasm characterization
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