CONICET | Buscador de Institutos y Recursos Humanos

AbstractCorn Stunt is an important disease in the Americas due to it high prevalence and the yieldreductions that can cause when present. However, changes in the presence of this diseaseacross years hampers the effective identification of resistant genotypes to this disease. Toavoid the limitations of phenotypic selection under natural pressure, this research aimed todevise an effective strategy to screen disease-resistant genotypes in the absence of highand constant natural pressures. To do so, we investigated the presence of antixenosis andantibiosis as components of resistance to the vector Dalbulus maidis as well as resistanceto the pathogen Spiroplasma kunkelii under artificial inoculation conditions in four maizehybrids. The hybrids shown differences in their levels of resistance and target organisms,either the insect vector or the pathogen. Antixenosis and antibiosis to D. maidis wereobserved in DK72-10. Resistance to S. kunkelii by DK79-10 was seen as a delayed onset ofsymptoms, and DKB390 showed antixenosis to D. maidis and resistance to S. kunkelii. Anassociation between symptom severity and yield reduction was found, but not betweenaccumulation of pathogen S. kunkelii and symptom severity nor yield. In conclusion, the proposedmethodology was efficacious and can aid in the screening of resistant genotypes inbreeding programs to reduce the impact of Corn Stunt disease, ensuring that hybrids withgood resistance level will be planted by farmers whenever disease occurs.