Submitted to: Corn Conference Interregional Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 2/11/2004
Publication Date: 2/12/2004
Citation: Pollak, L.M., Montgomery, K., Abel, C.A., Williams, W.P., Xu, W. 2004. Correlations between grain composition and pest resistance in a set of corn hybrids. Corn Conference Interregional Proceedings. Available: http://www.corn2.agron.iastate.edu/NCR167/Meetings/2004/2004NCRAgenda.htm. Interpretive Summary:
Technical Abstract: As we change seed chemical composition through breeding, we want to prevent undesirable correlated traits impacting production. Previously, we found that oil composition was correlated with seed quality in a set of germplasm. To determine if seed chemical composition affected disease or insect resistance, we evaluated a set of 20 diverse hybrids in five locations. Commercial or near-commercial hybrids were selected from 230 evaluated by NIR to for wide variation in grain quality. Three had average values, and Bt and non-Bt variants were included. Each location conducted disease and insect evaluations in 2002 and 2003 for which it had resources and expertise. In addition, each location self pollinated the hybrids for chemical composition. In 2003 European corn borer (ECB) evaluations in Ames, a slight negative correlation between first generation ratings and oleic acid content was found using only non-Bt entries. In ECB evaluations in Clinton in 2002, there were several significant correlations between composition traits and second generation ratings using only non-Bt entries. There were no significant correlations with oleic acid. An explanation for this result may be that five parental lines out of the 23 total were developed at Clinton and selected for native ECB resistance. In Lubbock, there was a significant correlation between oleic acid content and corn earworm ratings using all entries. An explanation may be that all the Bt entries came from three parents, one of which is high as a line for oleic acid and contributes high oleic acid to its hybrids. The entries selected for extremes from the 230 hybrids showed that a single hybrid was often extreme for more than one trait, and that an inbred can be a parent in two hybrids extreme for different traits. This preliminary analysis indicates that there may be correlations worth further investigation for insect resistance and oil quantity and quality.