Aislamiento, caracterización cultural y morfológica de aislados monospóricos del agente causal del moho gris de la hoja de Solanum lycopersicum L. en la provincia de Tungurahua.

Abstract

Gray leaf mold, caused by the ascomycete fungus Passalora fulva (Cooke) U. Braun & Crous (anamorph: Cladosporium fulvum), is one of the most common fungal diseases affecting tomato cultivation in Ecuador. This study aimed to isolate monosporic cultures from tomato leaves exhibiting signs of gray leaf mold and characterize them culturally and morphologically. The investigation was conducted in the Tungurahua province, where samples were collected from eight municipalities. Eighty monosporic isolates of C. fulvum were obtained from leaves affected by gray mold. The fungal isolates exhibited olive-green colonies on the obverse and black on the reverse, with raised surfaces, felty texture, and irregular shape. The majority of isolates displayed lobed edges. No pigmentation or exudates were observed in the colonies. Mycelial growth was measured at 7 and 14 days, with average velocities of 0.93 mm/day and 1.23 mm/day, respectively. The average hyphal diameter was 5.41 µm, while conidiophores had an average size of 33.01 µm, and conidia measured 6 µm in length and 5 µm in width. These characteristics correspond to the reported morphological descriptions of C. fulvum. Keywords: Cladosporium fulvum, cultural characterization, gray mold, tomato, morphology