Fusarium species from tropical grasses in Brazil and description of two new taxa

Abstract

Fusarium isolates were obtained from asymptomatic seeds of wild grasses collected in six regions of Brazil. Eleven phylogenetic species were identified among 41 isolates based on sequences of EF-1α. These are members of the F. fujikuroi (FFSC, n = 24), F. incarnatum-equiseti (FIESC, n = 13), and F. chlamydosporum (FCSC, n = 5) species complexes that encompass known plant pathogens, mycotoxigenic species, and endophytes. Phylogenetic analyses based on EF-1α, RPB2, and TUB revealed two new species, F. caapi and F. brachiariae, that belong to the African clade of the FFSC and share main morphological features of F. mundagurra and F. nygamai. Another encountered isolate formed a singleton phylogenetic lineage within the FIESC. This survey shows that naturally occurring and cultivated grasses not only harbor a high diversity of known species, which are pathogens of maize, sorghum, rice, and sugarcane, but also novel Fusarium species.