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

Authors: JERNIGAN, KENDRA - Washington State University; GODOY, J - Washington State University; HUANG, M - Washington State University; ZHOU, Y - Washington State University; Morris, Craig; Garland-Campbell, Kimberly; ZHANG, Z - Washington State University; CARTER, A - Washington State University

Submitted to: Frontiers in Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/16/2018
Publication Date: 3/9/2018
Citation: Jernigan, K.L., Godoy, J.G., Huang, M., Zhou, Y., Morris, C.F., Garland Campbell, K.A., Zhang, Z., Carter, A.H. 2018. Genetic dissection of end-use quality traits in adapted soft white winter wheat. Frontiers in Plant Science. https://www.frontiersin.org/articles/10.3389/fpls.2018.00271/full.

Interpretive Summary: Kernel texture, water absorption, protein strength, and milling quality differentiate the end-products made with wheat (Triticum aestivum L.). Generally, hard wheat flours have higher gluten strength, damaged starch, and non-starch polysaccharides that lead to increased water absorption capacity, whereas soft wheat flours have lower gluten strength, damaged starch, and non-starch polysaccharides that lead to decreased water absorption capacity. Since laboratory milling and baking quality assays are destructive, laborious, and expensive, breeders routinely do not use these methods for selection in earlier generations. Higher throughput and more cost effective methods of screening earlier generation material are needed, such as smaller-scale tests or use of molecular markers. The objective of this study was to assess a regionally adapted germplasm for significant genetic marker-quality trait associations to several end-use quality traits. These results should further elucidate the genetic factors controlling soft wheat end-use quality.

Technical Abstract: Soft white winter wheat is used in foreign markets for various end products requiring specific end-use quality profiles. Phenotyping for end-use quality traits using can be destructive, costly, and time-consuming, so it is advantageous to use molecular markers to select experimental lines with superior traits. An association mapping panel of 480 Pacific Northwest soft white cultivars and advanced generation breeding lines was developed from regional breeding programs. This panel was genotyped on a wheat specific 90K iSelect single nucleotide polymorphism (SNP) chip. The raw output of the 90K SNP chip were clustered and filtered prior to any statistical analysis. The genotypic data was combined with best linear unbiased predictions (BLUPs) from historical phenotypic data of the breeding lines in the panel. Genome-wide association mapping using compressed mixed linear models in the GAPIT R package enabled associations to be made between the SNP markers and favorable end-use quality traits. Significant markers for multiple end-use quality traits were found on chromosomes 1B, 1D, 2D, 5A, 5B, and 7A. The significant marker-trait associations on chromosome 1B for break flour yield, total flour yield, water solvent retention capacity, and carbonate solvent retention capacity indicate that selection for end-use quality has differed between the sub-populations. Better understanding of the genetic factors impacting end-use quality enable breeders to more effectively discard poor quality germplasm and increase frequencies of favorable end-use quality alleles in their breeding populations.