Final Selection of Quality Protein Popcorn Hybrids

Quality Protein Popcorn (QPP) BC₂F₅ inbred lines were produced through an interpopulation breeding system between Quality Protein Maize dent (QPM) and elite popcorn germplasm. In 2019, five QPP F₁ hybrids were selected for further evaluation due to superior agronomics, endosperm protein quality, and popping quality traits. Though these BC₂F₅ QPP hybrids were phenotypically similar to their popcorn parents, the QPP cultivars conveyed slightly inferior popping characteristics when compared to the original popcorn germplasm. The objective of this study was twofold. First, BC₂F₅ inbred lines were crossed to their popcorn parents and BC₃F₄ inbred lines were produced for hybridization to test the agronomic, protein, and popping trait effects from an additional QPP by popcorn backcross. Second, BC₂- and BC₃-hybrids were simultaneously evaluated alongside ConAgra Brands^® elite cultivars and ranked for potential commercialization in the spring of 2020. These 10 QPP hybrids were grown alongside five ConAgra Brands^® elite popcorn cultivars in three locations and agronomic, protein quality, and popping quality traits were evaluated. Significant improvements in popcorn quality traits were observed in the QPP BC₃ cultivars compared to their BC₂ counterparts, and yield averages were significantly lower in BC₃-derived QPP hybrids compared to the BC₂ population. Protein quality traits were not significantly different between QPP backcrossing populations and significantly superior to ConAgra elite popcorn varieties. Utilizing a previously published ranking system, six QPP hybrids, three from the BC₂F₅ population and three from the BC₃F₄ population, were evaluated as candidates for final selection. The successful evaluation and ranking system methodology employed is transferable to other hybrid production and testing programs. Incorporating this analysis with concurrent sensory studies, two QPP hybrids were chosen as premier cultivars for potential commercialization.