Cercospora zeina is the main species causing gray leaf spot in southern and central Brazilian maize regions

Maize (Zea mays) fields from a tropical central (Goias state) and a subtropical south region (Parana state) of Brazil were surveyed for Cercospora species causing gray leaf spot (GLS), a foliar fungal disease of increasing concern to growers of the country. Single spore isolates were obtained from maize leaves showing GLS symptoms and species-specific primers were used for species identification. In addition, a phylogeny of isolates representative of each species was conducted based on partial DNA sequencing of the EF1-α, CAL, and HIS genes, and ITS-5.8S rDNA region. In the regional collections, Cercospora zeina was the dominant species in Goias (68/75 isolates) and Parana (73/75 isolates), followed by C. zeae-maydis and C. sorghi var. maydis, respectively. In three field collections of both states, C. zeina was the sole species found. The phylogenetic characterization of isolates representing C. zeina (n = 18), C. zeae-maydis (n = 6), and C. sorghi var. maydis (n = 2) confirmed the identity of the species and grouped them in well-supported clades.