Submitted to: International Plant Resistance to Insects Workshop Abstracts & Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: March 15, 1998
Publication Date: N/A
Technical Abstract: The western corn rootworm is a major insect pest in continuous corn production, but no viable alternatives to use of insecticides for its control are available. In 1996, we identified seven corn cultivars with reduced corn rootworm damage. Use of these resistance sources will likely require crossing them into elite, proprietary germplasm. To determine which of our germplasm sources had the best potential for contributing corn rootworm resistance to their progeny, each parental line was crossed with each of the other six lines and two susceptible cultivars and evaluated at three central Missouri locations. Plots were artificially infested with western corn rootworm eggs. Feeding damage was evaluated using a rating scale (1 = resistant, 6 = susceptible) when approximately half of the larvae had stopped feeding and pupated. Three of the nine parents contributed corn rootworm resistance to their respective progeny as indicated by significant, negative general combining ability effects. The significant general combining ability effects in the crosses suggest that when these three cultivars are crossed to a series of other parents, the progeny can be expected to have lower levels of corn rootworm damage. Thus, the cultivars can serve as a source of corn rootworm resistance for crossing into elite, proprietary germplasm so that this resistance can reach the grower.