An updated linkage map for hazelnut with new simple sequence repeat markers
European hazelnut (Corylus avellana L.) is important in the Willamette Valley of Oregon where the number of hectares has expanded in recent years following the release by Oregon State University of new cultivars resistant to eastern filbert blight (EFB). Microsatellite markers, also known as simple sequence repeat (SSR) markers, have been extensively used in the hazelnut breeding program for fingerprinting, diversity studies, mapping, and assignment of new EFB resistance sources to linkage groups. From the transcriptome sequence (Illumina) of 'Jefferson', 111 new polymorphic SSR markers were developed. The genome sequence (Illumina) of 'Jefferson' was mined for SSRs which were aligned with reads from seven additional cultivars (12×), resulting in 343 additional polymorphic SSR markers. The new SSR markers were characterized using 48 diverse hazelnut accessions genotyped with fluorescently labeled forward primers and capillary electrophoresis fragment sizing following post-PCR multiplexing. The SSR markers were mapped in the reference mapping population (OSU 252.146 × OSU 414.062, 138 seedlings) using JoinMap 4.1 software, along with previously mapped SSR and RAPD markers. Linkage maps were constructed for each parent and all 11 linkage groups using the BC1 format. Of the new SSRs, 54 from the transcriptome and 232 from the genome were segregated in the reference population and placed on the map. As in previous attempts, LG2R and LG7R showed a strong tendency to merge into a single large map, and segregation was distorted on LG11. A dense linkage map and the new SSRs will be useful in many applications. Current efforts are expected to add thousands of genotyping-by-sequencing (GBS) markers to the map.
Mehlenbacher, S.A. and Bhattarai, G. (2018). An updated linkage map for hazelnut with new simple sequence repeat markers. Acta Hortic. 1226, 31-38
microsatellite, Corylus avellana, filbert, genome sequence, transcriptome