The final collection of 881 lines varied in genetic complexity from F1 inbred lines to BC10 inbred lines (Fig. 2A). Of these, 768 lines were BC2 inbred or greater and as such can more accurately be considered NILs. The original mutation containing donor genotypes were assembled, characterized, and documented by the barley mutation research community over a 50-year period in the mid-20th century. They were represented by over 300 different barley accessions. However, approximately one-half of the mutations were identified in one of eight cultivated barley genotypes (cultivars; Fig. 2B). The remaining donors were represented in less than 20 NILs each. For simplicity, we refer to all 881 lines as the Bowman NILs.