Author
Williams, William | |
Matthews, Gerald - Boo |
Submitted to: Journal of Agriculture
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 6/20/2016 Publication Date: 7/5/2016 Citation: Williams, W.P., Matthews Jr., G.A. 2016. Diallel analysis of southwestern corn borer leaf feeding damage in maize. Journal of Agriculture. 2(1):010. Interpretive Summary: Southwestern corn borer is an important insect pest of corn in the southern United States. The larvae feed extensively within the leaf whorls of plants that are in the vegetative stages of growth. Later in the growing season, larvae feed on the developing ears and tunnel within the stalks. This reduces both the quantity and quality of harvestable grain. Corn germplasm lines with resistance to southwestern corn borer leaf feeding have been developed and released by USDA-ARS at Mississippi State, Mississippi. All possible crosses were made among 10 germplasm lines: five lines had been selected for resistance to southwestern corn borer damage and five lines were selected for other qualities. The lines selected for resistance sustained significantly less damage than the unselected lines. When used as parents of single crosses, the lines selected for resistance to southwestern corn borer imparted resistance to the resulting hybrids indicating desirable general combining ability for resistance. These lines could be used in corn breeding programs to develop hybrids with genetic resistance to southwestern corn borer. This resistance could complement transgenic technology or provide alternative to transgenic technology as a means of reducing southwestern corn borer damage while reducing the need for chemical insecticides. Technical Abstract: Southwestern corn borer [Diatraea grandiosella (Dyar)] is an important pest of maize in the southern United States. It feeds extensively within the leaf whorls of plants in the vegetative stages of growth. This reduces both the quantity and quality of harvestable grain. Germplasm lines with resistance to southwestern corn borer leaf feeding have been developed and released. A diallel cross was produced by making all possible crosses among five lines selected for resistance to southwestern corn borer and five lines selected for other qualities. The lines selected for resistance exhibited significantly less damage than the unselected lines. General combining ability was a highly significant source of variation in the inheritance of resistance among these lines, but specific combining ability was not. Estimates of general combining ability effects for the five lines selected for reduced southwestern corn borer damage were highly significant indicating that these lines could be useful in developing maize hybrids that sustain less damage from southwestern corn borer. |