Espécies de Fusarium associadas ao milheto granífero

Abstract

Grain millet is an important crop in arid and semi-arid regions, as it is a rustic plant that is resistant to drought and grows in soils with low fertility. The destination of the cereal is for animal and human food. Among the fungi that occur in association with the crop are Fusarium species that can cause disease or compromise the quality and safety of grains. The primary literature on the millet-Fusarium association is scarce, while there has been considerable expansion of the culture in Brazil in recent times. In this study, it was investigated which Fusarium species are associated with grain millet in Brazil, which species induce panicle mold and stem rot. About 160 isolates, obtained from panicles and stems with and without symptoms or signs, from different producing regions of Brazil, were characterized by evaluating their morphological markers, analysis of molecular phylogeny of sequences from the tef1 gene region, pathogenicity test and bioassay. It was possible to identify 13 different species of Fusarium, which belong to two distinct complexes. Fusarium neosemitectum and other species of the Fusarium incarnatum-equiseti FIESC species complex induce panicle mold in millet. Species from the Fusarium fujikuroi FFSC species complex may eventually produce mycotoxins and not induce the mold signal, while FFSC and FIESC species can induce stem rot. Based on the knowledge obtained, it is possible to identify and monitor the etiological agents, develop strategies to mitigate possible damage and contribute to phytosanitary management. It will also be possible to subsidize breeding programs aimed at selecting resistant hybrids.