Responses to selection of S5 inbreds for broad-based resistance to ear rots and grain mycotoxin contamination caused by Fusarium spp. in maize

PRESELLO, D. A.; PEREYRA, A. O.; IGLESIAS, J.; FAUGUEL, C. M.; SAMPIETRO, D.A.; EYHÉRABIDE, G. H.

EUPHYTICA

SPRINGER

Lugar: Dordrecht; Año: 2011 vol. 178 p. 23 - 29

0014-2336

Random S5 inbreds derived from three F2 maize (Zea mays L.) populations (L1934 x LP918, LP915 x LP2541 and L7310 x L7266) were selected for ear rot resistance after inoculation with a low fumonisin producing isolate belonging to F. proliferatum. The four less susceptible and the four most susceptible inbreds from each population were crossed and F1 seeds were pooled. Resistant and susceptible pools from each population were evaluated for disease severity (percentage of the ear visibly diseased) after inoculation with the isolate used for selection, and high toxigenic isolates belonging to F. verticillioides and F. graminearum. Grain mycotoxin concentration was assessed by ELISA. Differences in disease resistance to each fungus were observed between resistant and susceptible pools in most populations and environments indicating that selection after inoculation with a single species might be effective to develop broad-based resistance to Fusarium. Resistant pools exhibited, after inoculation with F. verticillioides, low grain fumonisin concentrations in most populations and years. Positive genotypic correlations between disease severity and fumonisin concentration (0.89 < rg