Stemborer resistance of maize (Zea mays L.) to identify resistance to the Mexican rice borer (Eoreuma loftini Dyar).

摘要

The purpose of this research was to screen European corn borer (Ostrinia nubilais (Hubner)), south western corn borer (Diatraea grandiosella (Dyar)) and exotic maize (Zea mays L.) germplasms in a partial diallel mating design to determine levels of susceptibility and genetics of resistance to the Mexican rice borer (Eoreuma loftini (Dyar)) in the field and compare laboratory and field experiments for resistance.;Higher levels of artificial infestations in Fall provided a better estimate of susceptibility among the genotypes and more significant differences among the parameters measured than infestations conducted in Spring. Both GCA and SCA were important for percent plant and internode infestation, broken and broken and lodged plants and stalk damage rating. Genes involved in resistance to plant and interode infestation, broken and lodged plants and stalk damage rating were additively and nonadditively inherited. Genes involved in reducing larval establishment on plants and percent broken plants were more nonadditively inherited.;Genotypes which had the highest general combining ability for resistance to reduce plant and internode infestation and larval establishment on plants were B52 and Antigua-1. B52 and MP701 contributed resistance to broken and broken and lodged plants. Larval head capsule measurements indicated larval development was slower on Antigua-1 and MP701. B52 and Antigua-1 had the best susceptibility ratings and rankings of parental cross means for six field parameters. Correlations among field parameters with broken plants were low.;The nonchoice callus test detected the presence of antibiosis mechanism of resistance and the genes involved in reducing larval growth on callus were additively and nonadditively inherited. The callus choice test did not detect preference or antibiosis mechanisms or resistance. Preference mechanism of resistance was detected in the excised leaf sheath choice test. Fewer larvae were selecting leaf sheaths of resistant sources and their single crosses. There was no difference in larval weights for the excised stalk section experiments. Correlation among field parameters with larval weights from laboratory experiments were too low to serve any use in prediction. Laboratory experiments did not rank genotypes similar to susceptibility classification results in the field.