Application of CRISPR/Cas9 technology in forages

Genome editing is an advanced genetic modification tool that facilitates the removal, insertion, or substitution of nucleotides in the genome of an organism for mutation induction. CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR‐associated protein 9) is the most widely used genome editing tool that can precisely modify the specific sequence of a genome. Significant progress has been made in the use of CRISPR/Cas9 for the genetic improvement of food crops. However, in forage crops, the use of CRISPR/Cas9 is still in the infant stage with limited understanding and application. This article reviews current advances in the establishment and application of the CRISPR/Cas9 system in alfalfa, summarizes the application of CRISPR/Cas9 in several other forage legume and grass species, and discusses the prospects of CRISPR/Cas9 in the genetic improvement of forage crops. Alfalfa plants were obtained by genome editing of the Stay‐green (MsSGR) gene and by RNA interference (RNAi) downregulation of MsSGR. The genome‐edited alfalfa showed a more consistent greenish appearance than the RNAi plants after dark treatment.