Fungi causing leaf spot diseases in Lolium multiflorum in Brazil

Leaf spot diseases caused by fungi pose a serious threat to forage crops due to the reduced photosynthetic area, which dramatically affects yields. Aiming to expand knowledge of fungi causing leaf spot diseases in ryegrass (Lolium multiflorum) from southern Brazil, a comprehensive survey was undertaken. Seven species of plant pathogenic fungi were encountered. All species were identified by using a polyphasic approach combining morphological, ecological, and molecular sequences of seven genomic loci (actin, calmodulin, glyceraldehyde 3-phosphate dehydrogenase, histone, ITS, LSU, and partial translation elongation factor 1-α). The pathogenicity of representative strains of each species was also tested after artificial inoculations. Cercospora sp. G, Colletotrichum plurivorum, and Exserohilum rostratum represent new-host associations, Bipolaris sorokiniana, Pyrenophora nobleae, and Pyricularia oryzae are newly reported for Brazil, and Curvularia lolii is newly described. These results form the basis to identify these diseases in the field, which in the future can help agronomists and farmers to design strategies for integrated control and management in crop-livestock production systems.