Aislamiento de hongos potencialmente micorrízicos presentes en tres especies de orquídeas epífitas nativas del cantón de Gualaceo, Azuay, Ecuador

Abstract

In this study, 19 strains of potential mycorrhizal fungi (MF) were isolated from the root system of three native orchid species in the Aguarongo Protected Forest: Cyrtochilum sp, Odontoglossum pardinum and Pleurothalis sp. Root samples were collected during the rainy season at an altitude range between 3183- 3218 m a.s.l. The processing of the samples and subsequent isolation of the colonies was carried out considering different criteria that allow a higher probability of the presence of MF. Sixty samples were obtained by collecting 20 root fragments per species three root sections: basal (A), middle (B) and apical (C). Fungi Insolation Medium was used to evaluate the growth of potential MF colonies, which were then selected, isolated and purified on Potato Dextrose Agar medium. Viable and contamination-free cultures were subjected to a macroscopic and microscopic evaluation to identify morphological characteristics that define them as potential MF colonies. Although a greater number of pelotons were observed from section A (basal) of the root, the greatest number of potential MF strains resulted from section B (middle). Finally, the isolation of three possible genera of mycorrhizal fungi was achieved: Ceratobasidium, Tullasnella and Sebacina, the first being the most abundant possible genus among the isolated strains. The greatest number of potential MF were isolated from the epiphyte Odontoglossum pardinum. The results of this research will allow the promotion of a potentially mycorrhizal fungal species bank, useful for improving orchid symbiotic propagation protocols.