Evaluation of resistance of popcorn maize genotypes to fumonisin accumulation and fusarium ear rot

摘要

Fusarium ear rot, caused by the fungus Fusarium verticillioides , is one of the major diseases of popcorn maize ( Zea mays ) in Brazil and, besides reducing productivity, the action of the pathogen results in the contamination of grains by mycotoxins of the fumonisin group. The aim of this study was to evaluate the resistance of popcorn genotypes to fusarium ear rot and to the accumulation of fumonisins in the grains. The experiment was conducted in the field by adopting a randomized block design. Pathogen inoculation in the ear was artificial. Among the 22 evaluated genotypes, which included 16 progenitor lines and 6 varieties, there were significant differences (p = 0.05) in relation to the levels of fusarium rot and the accumulation of fumonisins B1, B2 and B3 in the grains. Spearman’s correlation for these variables was positive, but the correlation coefficients were low (r = 0.53; p 0.0002), showing that for this group of genotypes the quantification of fusarium ear rot has a small predictive value in relation to fumonisin content in the grains. This piece of information is believed to be useful for breeding programs of popcorn maize in Brazil.