Submitted to: Journal of Agricultural and Urban Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/1/2008
Publication Date: 4/1/2009
Citation: Matthews Jr., G.A., Williams, W.P., Daves, C.A. 2009. Diallel Analysis of Corn Earworm (Lepidoptera: Noctuidae) Resistance in Maize. Journal of Agricultural and Urban Entomology. 24:59-66. Interpretive Summary: Corn earworm is a major pest of corn in the United States. Nine inbred lines were evaluated for resistance to ear damage after infestation with newly matched larvae. Two lines, Mp313E and Mp717, exhibited resistance to ear damage. Fewer and smaller larvae were recovered from these lines 10 days after infestation. When these lines were used as parents to produce hybrids, larval growth was reduced on the resulting hybrids. Mp313E and Mp717 could be used in the development of corn earworm resistant corn germplasm. These lines were selected for resistance to aflatoxin accumulation in grain. They should be especially useful in producing corn hybrids for areas that require resistance to both corn earworm feeding and aflatoxin accumulation.
Technical Abstract: Corn earworm, Helicoverpa zea Boddie, is a major pest of maize in the United States. Host plant resistance is widely considered a desirable method for reducing losses to this pest. Nine inbred lines were evaluated for resistance to ear damage, larval survival, and weight of larvae. Mp313E and Mp717 sustained less damage than the other lines, and larval survival and growth on these lines was reduced. Analysis of a diallel cross among the nine lines indicated that both general combining ability (GCA) and specific combining ability (SCA) were significant sources of variation in the inheritance of resistance to ear damage. GCA was also a significant source of variation in the inheritance of resistance to larval growth. GCA effects for reduced larval weight were significant for Mp313E and Mp717. These lines could be useful in the development of maize hybrids with corn earworm resistance.