Trichoderma harzianum in vitro mycoparasitism on Peronospora belbahrii in basil (Ocimum basilicum)

Resumen

Objective: To describe the symptomatology and to identify the mildew causal agent in basil (Oscimum basilicum), as well as the Trichoderma harzianum-Peronospora belbahrii in vitro mycoparasitic activity.

Design/methodology/approach: Samples were taken from Nufar basil cultivars that had been naturally infected by mildew and, afterwards, the causal agent was isolated in order to carry out a pathogenicity test. The T. harzianum-P. belbahrii parasitism stages were observed in samples from the area in which both microorganisms interact.

Results: The disease symptoms that reveal the presence of a mildew causal agent on basil plants grown in pots and soil match Peronospora belbahrii. Subsequently, the Trichoderma hyphae rolled up and penetrated and vacuolated the conidiophores and the pathogen mycelium.

Study limitations/implications: This study was carried out using only one variety of basil.

Findings/conclusions: T. harzianum’s capacity to parasitize P. belbahrii in vitro was observed after 72 h. Once the conidium of the antagonist germinated, the hyphae directed their chemotropism growth towards P. belbahrii’s conidiophores and mycelium.