A Draft Genome and High-Density Genetic Mapof European Hazelnut (Corylus avellana L.)

Abstract

European hazelnut (Corylus avellana L.) is of global agricultural and economic significance, with genetic diversity existing in hundreds of accessions. Breeding efforts have focused on maximizing nut yield and quality and reducing susceptibility to diseases such as Eastern filbert blight (EFB). Here we present the first sequenced genome among the order Fagales, the EFB-resistant diploid hazelnut accession Jefferson (OSU 703.007). We assembled the highly heterozygous hazelnut genome using an Illumina only approach and the final assembly has a scaffold N50 of 21.5kb. We captured approximately 91 percent (345 Mb) of the flow-cytometry-determined genome size and identified 34,910 putative gene loci. In addition, we identified over 2 million polymorphisms across seven diverse hazelnut accessions and characterized t heir effect on coding sequences. We produced t wo high-density genetic maps with 3,209 markers from an F1 hazelnut population, representing a five-fold increase in marker density over previous maps. These genomic resources will aide in the discovery of molecular markers linked to genes of interest for hazelnut breeding efforts, and are available to the community at https://www.cavellanagenomeportal.com/.