Mycovirus-based biorational products for crop growth promotion and disease suppression

Overview

This research program focuses on developing mycoviruses—viruses that infect fungi—as innovative biorational products for agriculture. Two specific mycoviruses, SlaGemV-1 and SsHADV-1, are being evaluated as three distinct product types: soil inoculants (biofertilizers), seed treatments, and foliar spray biopesticides. Preliminary results show strong potential: a hypovirulent strain of Sclerotinia sclerotiorum infected with SlaGemV-1 has demonstrated the ability to promote dry bean growth when mixed into potting soil and to suppress fungal infection when applied as a foliar spray. Notably, SlaGemV-1 virion extracts have achieved up to 100% suppression of fungal infection in foliar applications, with a clear dose-response relationship.

The research aims to optimize delivery methods across multiple crop systems, offering a sustainable alternative to conventional chemical inputs. This approach aligns with growing market demand for environmentally responsible crop protection and plant health solutions.

Technical specifications

Core technology:

• Two mycoviruses (SlaGemV-1 and SsHADV-1) delivered via three application methods
• Hypovirulent fungal strain DK3-1.1mer infected with SlaGemV-1 serves as the primary delivery vehicle
• Viral particle extracts can be produced from fungal tissue for direct application

Delivery methods under investigation:

• Soil inoculum: Air-dried fungal tissue mixed into potting soil, later rehydrated and homogenized in water after cold storage at 4°C
• Seed treatment: Ground dry mycelia coating methods (an improvement over published wet mycelia protocols)
• Foliar spray: Crude virion extracts, optionally combined with common adjuvants for improved coverage and efficacy

Validation completed:

• Greenhouse assays on whole tomato plants through fruiting stage using DK3-1.1mer spray
• Growth chamber assays on dry bean plants with rehydrated tissue applications
• Field trials on soybean and dry bean using both foliar spray and seed treatment
• Greenhouse foliar spray trial of SlaGemV-1 virions on basil
• Ongoing field trial of SsHADV-1 virion extract with adjuvant on oilseed sunflower

Technology readiness level

The technology is at an advanced validation stage with greenhouse and field trials completed across multiple crops (tomato, dry bean, soybean, basil, and oilseed sunflower). Key efficacy data has been established for foliar spray applications, including demonstrated dose-response relationships and up to 100% fungal suppression in certain conditions. Seed treatment applications have shown less promising results to date, requiring further optimization. Next steps involve optimizing application rates and conditions across two moderately susceptible crop varieties, refining tissue production methods for crude viral particle extracts, and benchmarking performance against existing biorational products in the market. The program is positioned for collaborative development with industry partners to accelerate commercialization.