Degree Type

Creative Component

Semester of Graduation

Spring 2018

Department

Agronomy

First Major Professor

Dr. Thomas Lubberstedt

Second Major Professor

Dr. Marvin Paul Scott

Degree(s)

Master of Science (MS)

Major(s)

Plant Breeding

Abstract

The value of organically produced maize (Zea mays L.) is increased as traits such as nutrient content are improved (Berzonsky, 2000). For example, maize with high methionine and lysine concentrations, both critical to egg, meat and general bird health, may have the potential to reduce at least some fraction of synthetic additives (Moore et al., 2008; Adeyemo, 2012). In most grain crops, the protein component is lower than what is needed to meet dietary requirements of humans and most other non-ruminants (Peterson, 2000). Modern maize breeding and selection for large starchy kernels may have contributed to reduced concentration of essential amino acids (Jaradat, 2013). For people in developing countries, plant products with dietary provitamin A carotenoids such as β-carotene, βcryptoxanthin, and α-carotene are the major sources of vitamin A (West and Darnton-Hill, 2008). Organically produced nutrient-quality maize (NQM) may help alleviate human malnutrition and reduce the cost of organic feed. However, even if nutritional quality valueadded traits such as protein and carotenoids are determined to be stable in a genotype, the crop must be high yielding in order to compete in the marketplace. In this study we evaluated twenty genotypes of maize to determine if there is a correlation between protein, carotenoids and yield in hybrid and open pollinated (OP) varieties. Six of the twenty genotypes were hybrids developed under a pedigree breeding program for developing parent lines for organic corn production. The breeders selected specific germplasm from open-pollinated landraces as well as elite stiff stalk cultivars for performance, short season, high carotenoid and high protein content when grown under organic conditions. This group of genotypes is labeled as High Nutrient Hybrids (HNH). Seven of the twenty genotypes are high-yielding, certified organic commercial hybrid (CH) varieties grown in Iowa, Minnesota and Wisconsin. The last seven genotypes are open-pollinated varieties (OPV) selected for either their high yielding or high nutrient (protein and/or carotenoid) potential. We examined the variation in all twenty genotypes for carotenoid content, protein, starch, oil, density and grain yield in a replicated field trial experiment. New insights involving the relationship between pedigrees and yield were made. The HNH and OPV were found to contain a significantly higher protein content than the CH. The OPV Dziekuie contains a total-beta carotene content of two times the amount than the next highest in this study. CH genotype Viking® .90-.91, HNH pedigree PHK05.Ngor X LH119.LH123.11-2-2-4-2-1, and CH genotype Master Choice® 4050 hybrids performed highest for yield.

Copyright Owner

Zachary Paige

File Format

application/pdf

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