This project uses Teosinte Branched 1 (TB1) mutations to increase plant biomass and seed yield in elite wheat varieties. There are few known natural TB1 alleles for wheat and none that vary significantly in function. Furthermore, tight linkage between TB1 and Rht, a major height gene, has inhibited selection of new TB1 alleles. Our preliminary results indicate that reducing TB1 function increases productive tillers and plant biomass by >10%. Here, we will create BC5F4 NILs varying for TB1 alleles in spring, winter, and durum wheat standard and semi-dwarf backgrounds. We then will test all NILs across multiple locations, environments, and planting densities to identify TB1 allelic combinations best suited for growth in target environments. Our approach will maximize productive tillers and grain yield potential. All genotypes developed in this project will be transferred to wheat breeding programs and lead to yield enhanced varieties. This will benefit growers, the state, and national economy. Tillering potential is a fluid trait that can be quite resilient, with the ability to adapt to a changing climate. This is an ever-important quality when working toward US and global food security.