Biocontrol candidates myrothecium and penicillium for suppression of sclerotial pathogens in vegetable crops

Overview

Sclerotia are tough, overwintering fungal structures that enable pathogens such as Sclerotium rolfsii, Sclerotinia sclerotiorum, Verticillium, Macrophomina, and Botrytis cinerea to persist in soil and cause significant losses in vegetable crops. Researchers at the University of Tennessee, Knoxville have isolated and preserved strains of Myrothecium (Albifimbria) and Penicillium that demonstrated the ability to colonize sclerotia and inhibit germination of S. rolfsii in previous growth chamber and greenhouse trials. This project extends that work to evaluate the same isolates as broad-spectrum biological control agents, offering a potential alternative or complement to chemical fungicides for soil-borne disease management in tomato, lettuce, and pepper production.

Technical specifications

Key features:

• Myrothecium and Penicillium isolates previously recovered from organic-amendment soil trials that suppressed S. rolfsii sclerotia germination
• Isolates sequenced and preserved in culture collection for downstream testing
• Confrontation assays planned against multiple sclerotia-producing pathogens (S. sclerotiorum, Verticillium, Macrophomina, Botrytis cinerea)
• Spore inoculation method to assess sclerotia viability after antagonist exposure
• Growth chamber and greenhouse trials (n=8 pots) using inoculated sclerotia in soil with vegetable crops to measure disease suppression and plant performance
• Sclerotia survival assessment on potato dextrose agar (PDA) plates following inoculation

Technology readiness level

The isolates have been recovered, identified, and preserved following initial greenhouse and growth chamber observations of antagonism against S. rolfsii. The project is at an early experimental stage, with a planned six-month validation program including confrontation tests, viability assays, and crop performance trials. Successful completion will establish proof-of-concept efficacy across multiple sclerotial pathogens and provide the basis for further development toward a commercial biological control product or formulation.