Genetic gains from sixty years of spring wheat breeding in the northern plains of the U.S.

Authors: GILL, HARSIMARDEEP - University Of Minnesota; Blecha, Sarah; BRAULT, CHARLOTTE - University Of Minnesota; GLOVER, KARL - South Dakota State University; GREEN, ANDREW - North Dakota State University; COOK, JASON - Montana State University; LORENZ, AARON - University Of Minnesota; Read, Andrew; ANDERSON, JAMES - University Of Minnesota

Submitted to: bioRxiv
Publication Type: Pre-print Publication
Publication Acceptance Date: 5/25/2025
Publication Date: 5/23/2025
Citation: Gill, H.S., Blecha, S.M., Brault, C., Glover, K., Green, A., Cook, J., Lorenz, A., Read, A.C., Anderson, J.A. 2025. Genetic gains from sixty years of spring wheat breeding in the northern plains of the U.S. bioRxiv. https://doi.org/10.1101/2025.05.21.655386.
DOI: https://doi.org/10.1101/2025.05.21.655386

Interpretive Summary: The USDA-ARS coordinated Hard Red Spring Wheat Uniform Regional Nursery, established over 90 years ago, provides public and private wheat breeders an opportunity to test new germplasm across the spring wheat growing region each year. Results are summarized in publicly available reports after each growing season. The inclusion of consistent check cultivars and practices beginning in 1968 allows for a robust quantification of improvements in yield and other agronomic performance metrics over time. We analyzed this historical data and found that breeding efforts have led to wheat varieties that yield more without a negative impact on grain protein levels. Plants have gotten shorter and are flowering sooner, both desirable agronomic traits for U.S. wheat growers. Wheat breeders are selecting for varieties that are well suited for their target environments. These findings highlight the substantial long-term impacts of breeding efforts in Northern America and provide important information for refining future strategies to optimize breeding programs.

Technical Abstract: Assessing genetic gains over time is crucial for measuring the success of breeding programs and optimizing strategies for continuous improvement. Hard red spring (HRS) wheat is an important wheat class in the US and is primarily grown in the Northern Great Plains. Despite a long history of breeding efforts in this region, the long-term quantification of genetic trends for key traits has remained limited. This study analyzes over sixty years of data from the USDA-coordinated Hard Red Spring Wheat Uniform Regional Nursery (HRSWURN) to evaluate the genetic advancements in agronomic traits across multiple phases. A significant positive genetic trend of 0.61% per annum was observed for grain yield in HRS wheat from the Northern U.S. region. The realized genetic gain was 0.07% for test weight, -0.04% for days to heading, and -0.16% for plant height in the HRS region. Notably, sustained yield improvements have not impacted grain protein levels, showing that ongoing selection effectively balances productivity and end-use quality despite a negative correlation among these traits. Assessment of genetic trends over 20-year phases suggested slowing rates of genetic gains for grain yield but did not suggest any plateaus. The realized genetic gains were generally higher when breeding for target environments, with the public breeding program in Minnesota observing gains of ~1% per annum for grain yield when breeding for target environments. These findings highlight the substantial long-term impacts of breeding efforts in Northern America and provide important information for refining future strategies to optimize the breeding programs.