Biocontrol of strawberry Botrytis gray mold and prolong the fruit shelf-life by fumigant Trichoderma spp.

Abstract

Objectives To screen high active VOCs-producing Trichoderma isolates against strawberry gray mold caused by Botrytis cinerea, and to explore their antagonistic mode of action against the pathogen. Results VOCs produced by nine Trichoderma isolates (Trichoderma atroviride T1 and T3, Trichoderma harzianum T2, T4 and T5, T6, T7, T8 and T9 identified as Trichoderma asperellum by ITS sequencing in this work) significantly inhibited the mycelial growth (13.9 − 63.0% reduction) and conidial germination (17.6 − 96.3% reduction) of B. cinerea, the highest inhibition percentage belonged to VOCs of T7; in a closed space, VOCs of T7 shared 76.9% and 100% biocontrol efficacy against gray mold on strawberry fruits and detached leaves, respectively, prolonged the fruit shelf-life by 3 days in presence of B. cinerea, completely protected the leaves from the pathogen infection; volatile metabolites of T7 damaged the cell membrane permeability and integrity of B. cinerea both on water agar or on strawberry leaf surface, thereby inhibiting the mycelia growth, conidia germination and the formation of infection pads. Conclusions T. asperellum T7 showed high biofumigant activity against mycelial growth especially conidial germination of B. cinerea and thus protected strawberry fruits and leaves from gray mold, which acted by damaging the pathogen’s plasma membrane and resulting in cytoplasm leakage, was a potential biofumigant for controlling pre- and post-harvest strawberry gray mold.