Characterization of inbred corn lineages for resistance to the fall armyworm based on non-feeding preference and antibiosis
One of the pests that infests the corn crop (Zea mays) in Brazil is the fall armyworm (Spodoptera frugiperda, Lepdoptera: Noctuidae), considered its most important pest because of the significant damage produced. The use of resistant cultivars is an efficient control method. The objective of this work was to evaluate the mechanisms of resistance of non-feeding preference and antibiosis of newly hatched caterpillars on leaves of inbred corn lineages, derived from populations of commercial hybrid origins, Creole populations and semi-exotic populations. The no-choice non-feeding preference test was conducted in the laboratory, with three replications per 24 hours, using leaves of 169 corn lineages. For the antibiosis test, lineages that had a smaller leaf area consumed were selected and also lineages that had a larger leaf area consumed, which were sown in a greenhouse to proceed with leaf harvesting and the tests. Newly hatched larvae of S, frugiperda were fed daily, through the provision of leaves of the lineages evaluated with regard to biomass and length after 5, 10 and 15 days feeding. Besides presenting a non-feeding preference mechanism of resistance, lineages 94 and 137 also led to a change in the development of caterpillars, being promising to increase the efficiency of resistant cultivars in breeding programs.