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ARS Home » Midwest Area » Ames, Iowa » Corn Insects and Crop Genetics Research » Research » Publications at this Location » Publication #322745
Title: Genetic and agronomic assessment of cob traits in corn under low and normal nitrogen management conditions

Author
item JANSEN, CONSTANTIN - Iowa State University
item ZHANG, YONGZHONG - Maize Research Institute
item LIU, HONGJUN - Maize Research Institute
item GONZALEZ-PORTILLA, PEDRO - Iowa State University
item Lauter, Nicholas
item KUMAR, BHARATH - Iowa State University
item TRUCILLO-SILVA, IGNACIO - Iowa State University
item MARTIN, JUAN PABLO SAN - Pioneer Hi-Bred International
item LEE, MICHAEL - Iowa State University
item SIMCOX, KEVIN - Pioneer Hi-Bred International
item SCHUSSLER, JEFF - Pioneer Hi-Bred International
item DHUGGA, KANWARPAL - Pioneer Hi-Bred International
item LUBBERSTEDT, THOMAS - Iowa State University

Submitted to: Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/14/2015
Publication Date: 3/12/2015
Citation: Jansen, C., Zhang, Y., Liu, H., Gonzalez-Portilla, P.J., Lauter, N.C., Kumar, B., Trucillo-Silva, I., Martin, J., Lee, M., Simcox, K., Schussler, J., Dhugga, K., Lubberstedt, T. 2015. Genetic and agronomic assessment of cob traits in corn under low and normal nitrogen management conditions. Theoretical and Applied Genetics. 128:1231-1242. doi: 10.1007/s00122-015-2486-0.

Interpretive Summary: Exploring and understanding the genetic basis of corn cob biomass in relation to grain yield under varying nitrogen management regimes will help breeders to develop maize that can be used both for grain production for food and feed and for biomass feedstock for renewable energy. With rising energy demands and costs for fossil fuels, alternative energy from renewable sources such as corn cobs will become competitive. Corn cobs have beneficial characteristics for utilization as feedstock including compact tissue, high cellulose content, and low ash and nitrogen content. Nitrogen is quantitatively the most important nutrient for plant growth. However, the influence of nitrogen fertilization on maize cob production is unclear. In this study, genetic analysis of morphological traits such as cob weight, volume, length, diameter and density, as well as grain yield under normal and low nitrogen regimes was undertaken to address these important questions. One important finding was that the economics of cob usage under low nitrogen regimes is promising for balancing inputs versus outputs with respect to both profit margins for growers and reduction of environmental impacts.

Technical Abstract: With rising energy demands and costs for fossil fuels, alternative energy from renewable sources such as maize cobs will become competitive. Maize cobs have beneficial characteristics for utilization as feedstock including compact tissue, high cellulose content, and low ash and nitrogen content. Nitrogen is quantitatively the most important nutrient for plant growth. However, the influence of nitrogen fertilization on maize cob production is unclear. In this study, quantitative trait loci (QTL) have been analyzed for cob morphological traits such as cob weight, volume, length, diameter and cob tissue density, and grain yield under normal and low nitrogen regimes. 213 doubled-haploid lines of the intermated B73 × Mo17 (IBM) Syn10 population have been resequenced for 8575 bins, based on SNP markers. A total of 138 QTL were found for six traits across six trials using composite interval mapping with ten cofactors and empirical comparison-wise thresholds (P = 0.001). Despite moderate to high repeatabilities across trials, few QTL were consistent across trials and overall levels of explained phenotypic variance were lower than expected some of the cob trait × trial combinations (R2 = 7.3–43.1 %). Variation for cob traits was less affected by nitrogen conditions than by grain yield. Thus, the economics of cob usage under low nitrogen regimes is promising.