Genetic Mapping of Quantitative Trait Loci Associated with End-Use Quality Traits in the Spring Wheat (Triticum aestivum L.) Cross ‘Louise' by ‘Penawawa'.

Understanding the genetic factors underlying end-use quality traits in common wheat (Triticum aestivum L.) is essential to making gains from selection during the breeding process.  A set of 188 recombinant inbred lines from a ‘Louise’ by ‘Penawawa’ mapping population was grown in two crop years at two locations in the Pacific Northwest region of the United States and data was collected on 18 end-use quality traits.  Using an established genetic linkage map, composite interval mapping was used to identify QTL associated with 17 of the 18 quality traits.  QTL were found on 10 of the 21 wheat chromosomes.  A large number of QTL were located on chromosome 3B and 4D.  Chromosome 3B contained 13 QTL, the majority of which were localized to a 38.5 cM region.  Chromosome 4D contained 7 QTL, all of which were located on a 25 cM region of this chromosome.  The majority of the positive alleles for end-use quality were associated with the parent Louise.  The identification of these QTL for end-use quality gives key insight into the relationship and complexity of end-use quality traits.  It also improves our understanding of these relationships, thereby allowing plant breeders to make valuable gains from selection for these important traits.