Genetics of a diverse soft winter wheat population for pre-harvest sprouting, agronomic, and flour quality traits

Authors: PATWA, NISHA - Oak Ridge Institute For Science And Education (ORISE); Penning, Bryan

Submitted to: Frontiers in Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/2/2023
Publication Date: 6/6/2023
Citation: Patwa, N., Penning, B. 2023. Genetics of a diverse soft winter wheat population for pre-harvest sprouting, agronomic, and flour quality traits. Frontiers in Plant Science. 14. Article #1137808. https://doi.org/10.3389/fpls.2023.1137808.
DOI: https://doi.org/10.3389/fpls.2023.1137808

Interpretive Summary: Soft winter wheat is a staple crop of the North and South-central United States used in making many products including: cakes, cookies, crackers, biscuits, and pancakes. Over hundreds of years it has been bred to be adapted to this region and for yield, plant height, heading date, and pathogen resistance but rarely for pre-harvest sprouting resistance. However, in recent years acreage has fallen due to lower prices and weather-related crop losses from pre-harvest sprouting which can reduce crop value by a further 30%. To investigate the possibility of recovering breeding material that may have been lost over time that could improve the value of soft winter wheat grain and reduce losses due to pre-harvest sprouting, a population of breeding lines spanning over 200 years and collected to maximize the diversity contained in breeding lines from this time period was utilized. Information gathered in this study shows locations in the soft winter wheat genome that appear to have been selected for through time and overlap with agronomically important traits as well as those that could improve grain quality. Pre-harvest sprouting locations were found to be mostly independently located in eastern soft winter wheat and several new locations that may improve resistance were discovered. Finding locations in soft winter wheat breeding lines will benefit wheat breeders and lead to improved grain quality and pre-harvest sprouting resistance in soft winter wheat.

Technical Abstract: Soft winter wheat has been adapted to the north-central, north-western, and south-central United States over hundreds of years for optimal yield, height, heading date, and pathogen and pest resistance. Environmental factors like weather affect abiotic traits such as pre-harvest sprouting resistance. However, pre-harvest sprouting has rarely been a target for breeding. Owing to changing weather patterns from climate change, pre-harvest sprouting resistance is needed to prevent significant crop losses not only in the United States, but worldwide. Twenty-two traits including age of breeding line as well as agronomic, flour quality, and pre-harvest sprouting traits were studied in a population of 188 lines representing genetic diversity over 200 years of soft winter wheat breeding. Some traits were correlated with one another by principal components analysis and Pearson’s correlations. A genome-wide association study using 1,978 markers uncovered a total of 102 regions encompassing 226 quantitative trait nucleotides. Twenty-six regions overlapped multiple traits with common significant markers. Many of these traits were also found to be correlated by Pearson’s correlation and principal components analyses. Most pre-harvest sprouting regions were not co-located with agronomic traits and thus useful for crop improvement against climate change without affecting crop performance. Six different genome-wide association statistical models (GLM, MLM, MLMM, FarmCPU, BLINK, and SUPER) were utilized to search for reasonable models to analyze soft winter wheat populations with increased markers and/or breeding lines going forward. Some flour quality and agronomic traits seem to have been selected over time, but not pre-harvest sprouting. It appears possible to select for pre-harvest sprouting resistance without impacting flour quality or the agronomic value of soft winter wheat.