ABSTRACT
Pyricularia oryzae Cavara (syn. Magnaporthe oryzae B. C. Couch) (Couch and Kohn 2002) is a fungus that causes blast disease in more than 50 species of the Poaceae family (the grass family), including agricultural crops such as rice, wheat, barley, millet and oat (Urashima and Kato 1998; Couch and Kohn 2002; Takabayashi et al. 2002; Murakami et al. 2003; Couch et al. 2005; Prabhu and Filippi 2006; Castroagúdin et al. 2016). In Brazil, in addition to rice, the wheat crop is severely affected by outbreaks of the disease, especially in the states of Paraná, Minas Gerais, Mato Grosso do Sul, Mato Grosso, São Paulo and Goiás (Igarashi et al. 1986; Goulart and Paiva 1992; Anjos et al. 1996; Goulart and Paiva 2000). Wheat blast was first reported in Londrina, Paraná, Brazil, in 1985 (Igarashi et al. 1986). Reports of the rapid spread of the pathogen in other Brazilian states demonstrated the rapid dispersal of the pathogen from its original focus (Picinini and Fernandes 1990; Goulart et al. 1990; Goulart and Paiva 1992; Prabhu et al. 1992; Urashima and Kato 1994). Measures adopted for controlling wheat blast have not been effective, with no resistant wheat cultivars available and low efficiency of fungicides, conditions that are reflected in the losses caused by the disease, which may reach up to 100% (Goulart and Paiva 2000; Torres et al. 2009; Castroagúdin et al. 2015; Maciel 2011).
