Tiller number is a crucial determinant that significantly influences the productivity and reproductive capacity of forage. The regeneration potential, biomass production, and seed yield of perennial forage species are highly reliant on the development of tillering. Strigolactones (SLs) are recently discovered carotenoid-derived phytohormones that play a crucial role in the regulation of tillering in annual crops. However, the modulation of tiller growth in perennial forage by SLs remains insufficiently investigated. In this study, we identified two alleles of the SLs biosynthesis gene, DgCCD7