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

Every cultivar released in Nebraska must have four characteristics: improve d agronomic performance relative to existing cultivars, exceptional winterh ardiness, resistance to Puccinia graminis (the causal agent of stem rust), and acceptable end-use quality. This paper will discuss our strategy for br eeding cultivars with acceptable end-use quality. All experimental lines ar e derived from crosses with at least one or more parents with acceptable en d-use quality. As soon as individual lines are identified (F-5) 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, sampl es are composited from three or more locations/year, milled on a Buhler Mil l, and baked using 100 g of flour per loaf. Though genotype-by-environmenta l interactions are large for end-use quality traits, composite samples are satisfactory for determining the end-use quality when repeated over time. B y using phenotypic selection, the program has released cultivars with accep table 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 t o genotypic selection.