Genetic linkage maps remain very important tools for gene discovery in many plant species. Whilst several genetic maps exist for perennial ryegrass, it has been difficult to integrate data across studies because of a lack of a reference genome sequence and common genetic markers.
Velmurugan et al. have developed a dense SNP-based genetic map of a reference mapping population of ryegrass using genotyping-by-sequencing. All markers on the genetic map are anchored to a draft genome sequence of one of the grandparents of the F2 population; thus future genetics studies using the population will be comparable.
Janaki Velmurugan, Ewan Mollison, Susanne Barth, David Marshall, Linda Milne, Christopher J. Creevey, Bridget Lynch, Helena Meally, Matthew McCabe, Dan Milbourne, 2016, 'An ultra-high density genetic linkage map of perennial ryegrass (Lolium perenne) using genotyping by sequencing (GBS) based on a reference shotgun genome assembly', Annals of Botany, vol. 118, no. 1, pp. 71-87 http://dx.doi.org/10.1093/aob/mcw081