摘要The lack of genome editing platforms has hampered efforts to study and improve forage crops that can be grown on lands not suited to other crops.Here,we established efficient Agrobacterium-mediated clustered regularly interspaced palindromic repeats(CRISPR)/CRISPR-associated nuclease 9(Cas9)genome editing in a perennial,stress-tolerant forage grass,sheepgrass(Leymus chinensis).By screening for active single-guide RNAs(sgRNAs),accessions that regenerate well,suitable Agrobacterium strains,and optimal culture media,and co-expressing the morphogenic factor TaWOX5,we achieved 11%transformation and 5.83%editing efficiency in sheepgrass.Knocking out Teosinte Branched1(TB1)significantly increased tiller number and bio-mass.This study opens avenues for studying gene function and breeding in sheepgrass.