Development of an apple F₁ segregating population genetic linkage map using genotyping-by-sequencing

Genotyping-by-sequencing (GBS) has been used as a viable single nucleotide polymorphism (SNP) validation method that provides reduced representation sequencing by using restriction endonucleases. Although GBS makes it possible to perform marker discovery and genotyping simultaneously with reasonable costs and a simple molecular biology workflow, the standard TASSEL-GBS pipeline was designed for homozygous groups, and genotyping of heterozygous groups is more complicated. To addresses this problem, we developed a GBS pipeline for heterozygous groups that called KNU-GBS pipeline, specifically for apple (Malus domestica). Using KNU-GBS pipeline, we constructed a genetic linkage map consisting of 1,053 SNP markers distributed over 17 linkage groups encompassing a total of 1350.1 cM. The novel GBS pipeline for heterozygous groups will be useful for marker-assisted breeding programs, and diverse heterozygous genome analyses.