Aislamiento de microorganismos fungosos asociados al cultivo de tuna (Opuntia ficus-indica, (L.) Mill), en laboratorio de fitopatología de la facultad de recursos naturales.

Abstract

The present investigation aimed to isolate fungal microorganisms associated to the cultivation of Tuna (Opuntia ficus-indica (L.) Mill), at laboratory level that is why samples of complete cladodes were collected in different stages of development with presence of necrotic areas, chlorotic spots, cracks, pustules and presence of halos, in producing areas of the localities of Tunshi, Chingazos, Alacao and the main campus of the Escuela Superior Politécnica de Chimborazo in the province of Chimborazo. Fungi were isolated by sowing portions of the affected cladodes with characteristic lesions of fungal microorganisms previously disinfested in potato dextrose agar medium (PDA) that allowed promoting microbial growth and obtaining pure isolates of the same. A total of 44 fungal isolates were obtained, which were later identified based on cultural and morphological characteristics and the use of taxonomic keys from different authors. According to the growth form, mycelial coloration, and morphology of conidia, arthroconidia, hyphae and spores, different fungal isolates associated with prickly pear were identified. A great diversity of fungi was obtained, such as the genera Alternaria sp. with a prevalence of 50% in the different localities, genera 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 finally unidentified fungi (9.09%). This study is one of the first studies carried out in the province of Chimborazo on the microbiota associated to this important crop. New complementary studies are necessary to clarify the taxonomic position and role of the fungal microorganisms found in the different places.