Identificación y caracterización morfológica de hongos asociados a daños en tuna (Opuntia ficus-indica), en la provincia de Chimborazo, Ecuador

Abstract

This research aimed to identify and morphologically characterize fungi associated with symptoms in cultivating prickly pear (Opuntia) in Chimborazo, Ecuador. Samples of cladodes were collected at different growth stages, including immature and mature stages, exhibiting necrotic areas, chlorotic spots, fissures, pimples, and halos. Sampling was conducted in productive regions of Tunshi, Chingazos, Alacao, and the main campus of the Escuela Superior Politécnica de Chimborazo in the province of Chimborazo. Fungi were isolated by directly inoculating disinfested "affected" portions of cladodes. Potato Dextrose Agar (PDA) was used as the culture medium to obtain fungal isolates. A total of 44 isolates of filamentous fungi were obtained and identified based on their cultural and morphological characteristics using taxonomic keys. The predominant fungal genera among the isolates were Alternaria sp. (50%), followed by Fusarium sp. (9.09%), Scytalidium sp. (9.09%), Cladosporium sp. (6.82%), Geotrichum sp. (6.82%), Trichoderma sp. (4.55%), Armillaria sp. (2.27%), Rhizopus sp. (2.27%), and unidentified fungi (9.09%). This study represents the first report conducted in the province of Chimborazo regarding fungal species associated with this crop, paving the way for further complementary molecular studies to determine the taxonomic position of those isolates that could not be classified using taxonomic keys. Keywords: Characterization; Identification; Sympomatology; Causal Agents; Fungi