European hazelnutEuropean hazelnut (Corylus avellana L.) is a member of the family Betulacea, a group of six plant genera that include the birches (Betula L. spp.) and alders (Alnus Mill spp.). Hazelnuts provide the predominant flavor in a variety of butters, candies, chocolate spreads, and confectionary pastes and their shells are used for landscaping, groundcover, and fuel.
European hazelnut is a diploid with 11 chromosomes (2n =2x=22) and a genome of ~378 Mbp. We sequenced the ‘Jefferson’ genome at ~93× coverage and completed a de novo genome assembly, capturing ~91% of the genome (345 Mbp) with a contig N50 of 21,540 bp and an average length of 9,442 bp. Homology-based functional annotation predicted 34,910 protein coding loci, with 22,474 having homology to an entry in the NCBI non-redundant protein database. 82.5% of the annotated genes are presented in the best-annotated and most closely related genera Vitus, Prunus, Populus, and Ricinus. |
'Jefferson': the reference
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The hazelnut accession 'Jefferson' (OSU 703.007) was released in
2009 by Oregon State University.
‘Jefferson’ was selected as the reference hazelnut accession for genome
assembly and characterization due to its commercial importance and the presence
of a dominant allele from 'Gasaway', which confers resistance to the disease Eastern Filbert Blight (EFB).
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Resequencing of seven diverse hazelnut accessions
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Current high-throughput sequencing technologies enable rapid resequencing of whole genomes which is well-suited for polymorphism discovery among multiple accessions. We implemented this method to identify polymorphisms and explore sequence diversity among hazelnut accessions from various geographical regions, possessing different levels of resistance to EFB and desirable characteristics for breeding. Variants are color-coded based on putative impact on coding potential:
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Genetic linkage map
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The high-density genetic map was constructed from a full-sib population of 138 F1 plants and two parents (in triplicate) from the cross OSU 252.146 × OSU 414.062 using a two-way pseudo testcross approach. The improved map will be useful for marker-assisted breeding and the identification of new, desirable traits in hazelnut.
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Publications |
Rowley, E.R., Vanburen, R., Bryant, E.R., Priest, H.D., Mehlenbacher, S.A., and Mockler, T.C. 2018. A Draft Genome and High-Density Genetic Map of European Hazelnut (Corylus avellana L.). bioRxiv. doi: https://doi.org/10.1101/469015
Rowley, E.R., Fox, S.A, Bryant, D.W, Sullivan, C., Givan, S. A., Mehlenbacher, S.A., and Mockler, T.C. 2012. Assembly and characterization of the European Hazelnut (Corylus avellana L.) ‘Jefferson’ transcriptome. Crop Science. 52: 2679-2686 |