Characterization of Colletotrichum isolates causing anthracnose on Artocarpus heterophyllus in Brazil

Jackfruit ( Artocarpus heterophyllus ) is an important fruit crop in Brazil, and it is commonly found in commercial plantations or spontaneous plants across the whole country. Anthracnose caused by Colletotrichum spp. is among the most important diseases of jackfruit. However, it is unclear which Colletotrichum species is responsible for this disease in Brazil. In 2018, in Goiás, Paraná and São Paulo states, and Distrito Federal (Brazil), jackfruit leaves presented necrotic foliar lesions with dark edges, light center, and chlorotic halo. Incidence of diseased leaves per plant was low (1 to 5%) and lesions were concentrated on the older leaves. Eight Colletotrichum isolates obtained from symptomatic leaves were assigned to the species C. siamense based on phenotypical and molecular features. Their pathogenicity was confirmed by inoculation on jackfruit seedlings and reisolation of the pathogen from induced lesions. Also, the isolates were pathogenic to leaves of soursop, cashew, and mango, which indicates non-host specificity to the original host.