Evaluation of European hazelnut (Corylus avellana) genetic diversity using a genotyping-by-sequencing approach

Commercial hazelnut production is a growing industry that spans several continents. An increased understanding of the genetic backgrounds of prominent accessions would help breeders foster the development of this industry through the release of improved cultivars. While past studies have genotyped hazelnuts (Corylus sp.) using simple sequence repeat (SSR) markers, this study sought to genotype accessions using single nucleotide polymorphism (SNP) markers generated through next-generation sequencing (NGS). Germplasm included in this study consisted of accessions spanning known European hazelnut diversity, including a significant subset from the Republic of Georgia, as well as accessions representing sources of resistance to eastern filbert blight (EFB). The resulting SNP markers were used to construct a STRUCTURE diagram to visualize the populations of the included accessions. Results showed that all accessions could be grouped into 3 or 9 populations depending on the parameter used for grouping. Compared to past SSR genotyping studies, there was significant restructuring of accessions across populations due to the greater number of SNP markers. This study shows the advanced capabilities of NGS and how its use of markers can be used to improve our collective knowledge of hazelnut diversity moving forward.