The presence and spectrum of light influences the in vitro conidia production of Mycosphaerella fijiensis causal agent of black Sigatoka

Black Sigatoka caused by Mycosphaerella fijiensis is the most important leaf disease affecting bananas and plantains in the world today. Conidia constitute one of the forms by which the disease is spread. Although light has been described as an important factor for conidial production in M.fijiensis, no detailed studies have been conducted. In a series of in vitro experiments, the production of conidia in different culture media and with different photoperiods and light spectra was assessed. Results showed that the best media for conidia production were potato dextrose agar and V8 juice agar + 0.2 g/L CaCO3. Light (15001x) was required for conidial production and the light spectrum used significantly influenced the number of conidia produced, with red light having the greatest positive effect.