Stenocarpella macrospora and Stenocarpella maydis in the cerrado and southern Brazil regions

Abstract

Stenocarpella macrospora and Stenocarpella maydis may result in the seedlings death or cause rotting at the corn stalk base and in all or part of the ear. In addition, S. macrospora can cause leaf spot. Double-haploid strains from corn hybrids resistant to S. macrospora and S. maydis were identified. Also the incidence of these pathogens in the Cerrado and in Southern Brazil localities was determined. One hundred and forty double-haploid maize hybrids, in addition to the controls, were inoculated with S. macrospora and S. maydis and evaluated for resistance reaction in three locations of the Cerrado and three locations of the South regions. The grains attacked by these fungi were collected and variable quantities of S. macrospora, S. maydis and other fungal species were registered. The results demonstrated the prevalence of S. macrospora in the Cerrado as well as other non-Stenocarpella sp. fungi in the South. The city of Abelardo Luz (Santa Catarina) was the only place where S. maydis was found to have a higher incidence than S. macrospora. Environmental effects influence the prevalence of fungi, causing grain rot. These results indicated genetic gains in the selection of hybrids resistant to this fungi for use as direct breeders in Stenocarpella-corn pathological system research.