Identification of Epicoccum poaceicola causing eggplant leaf spot and its cross-infection potential to other solanaceous vegetable crops

Abstract

This study characterised and identified the causative agent of irregular necrotic leaf spots in eggplant. The culture characteristics and morphology of three fungal isolates indicate that they are from the Didymellaceae group. Using a polyphasic approach—combined morphological, cultural, pathogenicity, and molecular characterisation (concatenated sequences of three gene loci: ITS, TUB2, LSU), the fungal isolates MBELIQ03A and MBELIQ03D were identified as Epicoccum poaceicola. Isolate MBELIQ02 was identified as Epicoccum sp. due to a lack of clear grouping with a single Epicoccum species. In repeated trials, the three Epicoccum isolates were pathogenic to eggplant leaves in detached leaf assays. Similar fungi were consistently re-isolated from the inoculated leaves and thus, establishing Koch’s postulates. Inoculation of the three isolates on solanaceous leaves and fruits (tomato, eggplant, and pepper) revealed their varied pathogenicity. This is the first confirmed scientific report of Epicoccum poaceicola causing eggplant leaf spots. This is also the first record of this fungal species in the Philippines. Inoculum from leaf infection could serve as inoculum for fruit infection and other solanaceous vegetable crops grown nearby a field planted with eggplant.