Inheritance of Ear Resistance to European Corn Borer in ‘Apache’ Sweet Corn
1998
Warnock, D. F. | Davis, D. W. | Gingera, G. R.
European corn borer, Ostrinia nubilalis (Hǖbner), can severely affect commercial sweet corn (Zea mays L.) quality during years of heavy infestation. Greater ear resistance in sweet corn could reduce the need for insecticide application. A generation mean analysis was used to determine the inheritance of ear resistance and silk-channel length (SCL) in two crosses containing germplasm from the resistant sweet corn hybrid ‘Apache’. Three inbred parents, F₁, F₂, and the first backcross populations were manually infested and visually evaluated in field experiments. For each cross, ear damage, SCL, and number of surviving larvae differed (P ≤ 0.05) among generations. The genetic effects affecting the variation for ear resistance ranged from epistatic (Cross 1) to additive-dominance (Cross 2). Silk-channel length was controlled by epistatic (Cross 1 and Cross 2) effects. Inheritance of these traits is complex, probably involving multiple genes. As the silk channel often is the point of larval entry, SCLs were hypothesized to be important in ear resistance. The low to moderate correlations (P ≤ 0.01) across generations within each cross between ear damage and SCL (r = −0.18 and −0.75), surviving larvae (r = 0.78 and 0.79), and number of larvae in each third of the ear (r = 0.64−0.84) suggest that extending the SCL is not the sole component responsible for ear resistance. Minnesota Agricultural Experiment Station Journal series no. 971210006. Support for this research was provided in part by a grant from the Midwest Food Processors Association.
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