Adaptation of Quality Protein Maize (Zea Mays L.) to Northern U.S. Corn Belt

There is a need to increase the value of crops and develop the next generation of healthier products. Quality protein maize (Zea mays L.) is an option but has never been adapted to short ? season environments. Quality protein maize (QPM) with homozygous embryo and endosperm for mutant allele o2 at the ?-zeins regulatory gene opaque-2 shows about 60 to 100% increase in lysine and tryptophan essential amino acids when comparing with non-QPM maize. The objectives of this research were to adapt QPM genotypes to the northern U.S. through the NDSU Early QPM Program, and to evaluate the agronomic potential of early generation QPM lines and hybrids developed by the NDSU maize breeding program for the northern USA. Fifty-four inbred lines, including 47 QPM donor lines from the Iowa State University (ISU) maize breeding program, six experimental lines from the NDSU maize breeding program and one ex-PVP line from industry, were selected to produce 94 early-QPM backcross populations. Based on the earliness, protein content, and amino acid levels of lysine, 218 BC1S2 lines were selected for testcrosses with industry testers. Experiments evaluating testcrosses were arranged in 12 x 12 and 10 x 10 partially balanced lattice designs across three environments in 2013 and 2014. Based on this evaluation, totally 48 S2 lines were selected for further development, 17 of them representing the Stiff Stalk (SS) heterotic group and 31 representing the non-SS-group. Selected lines provided unique advanced inbred lines with hybrid combinations showing not only above average grain yield, dry down, and protein content but also, high levels of lysine, tryptophan, and methionine. The results of this research show, for the first time, the successful adaptation of QPM genotypes to short-season environments. The NDSU maize-breeding program has developed the first high quality maize products through the EarlyQPM and EarlyQPMF (for feedstock) national programs.North Dakota Corn Growers AssociationMinnesota Corn Growers Associatio