BioSample

The hemibiotrophic Ascomycetous fungus (class of dothideomycetes) Pseudocercospora musae (Zimm.) Deighton (Pm) [sexual morph: Mycosphaerella musicola R. Leach ex J.L. Mulder], is the causal agent of Yellow Sigatoka disease on banana. The pathogen was first reported in the Indonesian island of Java in 1902 but today it is spread to almost all banana producing areas of the world, occasionally causing severe epidemics. Typical symptoms of the disease include small yellow streaks on the upper side of infected leaves that gradually merge to form larger lesions that turn necrotic with light gray centers and yellow perimeters. The host range of the pathogen is believed to be restricted to Musa spp, with desert bananas (AAA) of the Cavendish-subgroup being generally susceptible, and most cooking bananas and plantains (AAB and ABB) being moderately to highly resistant. The fungus is also known to reproduce asexually through the production of conidiophores on both sides of the infected leaves that give rise to water-dispersed conidia, and sexually through the formation of asci that contain the wind-dispersed ascospores. Although Yellow Sigatoka has a worldwide distribution, currently the pathogen is being replaced by the more aggressive Pseudocercospora fijiensis (sexual morph: Mycosphaerella fijiensis), which causes a disease known as Black Sigatoka. Yellow Sigatoka, however, remains the dominant disease at higher altitudes (>1200 m), as the pathogen is better adapted at lower temperatures and lower relative humidity. The two pathogens together with Pseudocercospora eumusae (sexual morph: Mycosphaerella eumusae), causal agent of eumusae leaf spot disease, are the primary constituents of the Sigatoka disease complex on banana, currently the biggest threat to the banana production worldwide.

Keywords: GSC:MIxS;MIGS:6.0