Targeted Mutagenesis in Ryegrass (Lolium spp.) Using the CRISPR/Cas9 System.

Ryegrass is one of the most important forage crops worldwide. It is the basis for 80% of milk production and 70% of meat production, and has major economic importance. Breeding programs for ryegrass started in the 1920s, and breeders have mainly relied on repeated phenotypic and recently genotypic selection of elite individuals. Although this approach has led to significant improvements in several characters including rust resistance, spring growth, and aftermath heading, it tends to be laborious, expensive and time consuming, mainly due to gametophyte self-incompatibility in most ryegrass species (Sampoux et al., 2011).