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ARS Home » Midwest Area » Columbia, Missouri » Research » Publications at this Location » Publication #407989
Title: Characterization of southeastern United States open-pollinated maize landraces

Author
item WOORE, MATTHEW - North Carolina State University
item Flint-Garcia, Sherry
item Holland, Jim - Jim

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/4/2024
Publication Date: 3/17/2024
Citation: Woore, M.S., Flint Garcia, S.A., Holland, J.B. 2024. Characterization of southeastern United States open-pollinated maize landraces. Crop Science. 64:772-787. https://doi.org/10.1002/csc2.21198.
DOI: https://doi.org/10.1002/csc2.21198

Interpretive Summary: Heirloom corn varieties offer an alternative to hybrid corn for niche end uses such as craft distilling and local food processing. Heirloom varieties are unimproved corn populations that may contain unique grain characteristics which have been lost during modern corn breeding for high yield. Heirloom varieties exist in seed repositories but are not well characterized. In this study, we evaluated 76 heirloom varieties in Missouri, North Carolina, and South Carolina for a large number of agronomic and productivity traits. We found that the heirloom varieties have a broad range of variation that can be used to improve heirlooms to be more productive and have grain characteristics of value to end users. We also found common names are not useful predictors of how heirlooms are related or of their value. Finally, we found that prior reports of relationships among heirloom varieties may not be accurate, thus warranting further studies of the larger heirloom collection. The results of this study are valuable to geneticists and breeders working to develop heirloom corn varieties for specific food and beverage uses, ultimately adding value to the corn crop for small-scale farmers and rural communities.

Technical Abstract: Maize (Zea mays L. subsp. mays) is the most important crop in the United States, but maize food and distillation products often rely on varieties that are not bred explicitly for these purposes. Farmers targeting niche food grain markets have expressed interest in historical open-pollinated varieties of maize, but few such populations are widely available, and even fewer are well-characterized. We planted field trials of 76 open-pollinated heirloom varieties available from seed catalogs and the United States Department of Agriculture germplasm collection along with four F1 hybrid cultivars. We measured 24 traits across 3 years and three locations to characterize the selected varieties and measure their phenotypic relationships. We identified a subset of 19 traits with heritability >0.5 and pairwise correlation coefficients not exceeding 0.9 for phenotypic analysis. Our results demonstrate that many historical accessions contain substantial genetic variation that should permit improvement from within-population selection. Variety name and origin are often not useful indicators of phenotypic relationships or potential crop value, although Hickory King varieties have maintained their identity even following global dispersion. Cluster analysis identifies nine morphologically distinct groups within the varieties tested, which are largely in agreement with previously proposed landrace groupings. Our results suggest a complex intermixing of Southern Dents with other maize types, rather than a clear distinction between Southern Dents and Derived Southern Dents, however. Genetic analysis of larger samples of US open-pollinated populations will help better define the natural classification of maize indigenous to the United States.