Genetic architecture of end-use quality traits in soft white winter wheat

Authors: AOUN, MERIEM - Washington State University; CARTER, ARRON - Washington State University; Morris, Craig; Kiszonas, Alecia

Submitted to: BMC Genomics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/4/2022
Publication Date: 6/24/2022
Citation: Aoun, M., Carter, A.H., Morris, C.F., Kiszonas, A. 2022. Genetic architecture of end-use quality traits in soft white winter wheat. BMC Genomics. 23. Article 440. https://doi.org/10.1186/s12864-022-08676-5.
DOI: https://doi.org/10.1186/s12864-022-08676-5

Interpretive Summary: End-use quality improvement in wheat is one of the primary objectives in wheat breeding programs to meet the requirements of grain markets, millers, and bakers. End-use quality is complex and involves several components. This includes grain hardness, which is a key determinant of end-use quality where hard wheat is mainly used for making bread, and soft wheat is primarily used for making cookies, cakes, confectionery products, and Asian-style noodles. This study used historical data that captured a wide range of phenotypic variation for end-use quality within soft white winter wheat. Heritability estimates for end-use quality traits were moderate to high except for grain and flour protein. This suggests that most traits are largely controlled by genetic factors, thus genetic gains in end-use quality can be achieved. This study identified the genetic factors underlying 14 end-use quality traits in current breeding lines and cultivars from WSU soft white winter wheat breeding program. This study provides information that can be exploited to widen the range of traits/molecular markers used to breed for end-use quality in soft white winter wheat.

Technical Abstract: Genetic improvement of end-use quality is an important objective in wheat breeding programs to meet the requirements of grain markets, millers, and bakers. However, end-use quality phenotyping is expensive and laborious thus, testing is usually delayed until advanced generations. With the decreasing cost of genotyping technologies, molecular markers can help selection for end-use quality in earlier generations. However, to date, marker-assisted selection (MAS) for end-use quality traits has been limited to few major genes. To widen the use of MAS to different end-use quality traits, we investigated the phenotypic and genotypic structure of 14 end-use quality traits in 672 advanced soft white winter wheat breeding lines and cultivars adapted to the Pacific Northwest region of the United States. This collection had continuous distributions for the 14 end-use quality traits. The breeding lines and cultivars were genotyped using genotyping-by-sequencing and 40,518 SNP markers were used for association mapping (GWAS). The GWAS identified 178 marker-trait associations (MTAs) distributed across all wheat chromosomes. A total of 40 MTAs were positioned within genomic regions of previously discovered end-use quality genes/QTL. Among the identified MTAs, 58 had larger effects and thus should be prioritized in breeding for end-use quality in soft white wheat. We also identified 17 loci associated with two or more traits, which offers an opportunity for simultaneous breeding for multiple end-use quality traits. MTAs from this study can expand the range of traits/molecular markers used for end-use quality breeding in soft white winter wheat.