Breeding for end-use quality: Reflections on the Nebraska experience

Every cultivar released in Nebraska must have four characteristics: improved agronomic performance relative to existing cultivars, exceptional winterhardiness, resistance to Puccinia graminis (the causal agent of stem rust), and acceptable end-use quality. This paper will discuss our strategy for breeding cultivars with acceptable end-use quality. All experimental lines are derived from crosses with at least one or more parents with acceptable enduse quality. As soon as individual lines are identified (F5) generation, microquality analyses are conducted and approximately 10% are discarded on the basis of poor end-use quality. In the F 6 and later generations, samples are composited from three or more locations/year, milled on a Buhler Mill, and baked using 100 g of flour per loaf. Though genotype-by-environmental interactions are large for end-use quality traits, composite samples are satisfactory for determining the end-use quality when repeated over time. By using phenotypic selection, the program has released cultivars with acceptable quality involving known ‘poor’ quality genes and chromosomes, such as high-molecular weight (HMW) glutenin subunits 2+12 (Scout 66 and Lancota), 1BL.1RS (heterogeneous in Rawhide and homogeneous in Cougar), and 1AL.1RS (heterogeneous in Nekota and Niobrara). Phenotypic selection is preferred to genotypic selection