Molecular Real-Time PCR Monitoring of Onion Fusarium Basal Rot Chemical Control

Area of Science:

• Plant Pathology
• Agricultural Science
• Molecular Biology

Background:

• Fusarium basal rot (FBR) is a significant onion crop disease globally, causing yield loss and post-harvest rot.
• FBR is an emerging threat in Israel, necessitating effective disease management strategies.
• Previous studies explored chemical protection, but pathogen dynamics within the host require further investigation.

Purpose of the Study:

• To molecularly track Fusarium pathogens within onion plants using real-time qPCR.
• To compare the efficacy of different chemical treatments on plant health and infection levels.
• To optimize chemical application strategies for season-long Fusarium basal rot control.

Main Methods:

• A full-season pot experiment was conducted using two commercial onion cultivars.
• Real-time quantitative PCR (qPCR) was employed to monitor pathogen loads within plant tissues.
• Plant growth and health indexes were analyzed alongside molecular data to assess treatment impacts.

Main Results:

• All tested chemical treatments reduced pathogen infection by 80-90%, indicating broad efficacy.
• Specific fungicide combinations (e.g., Azoxystrobin + Tebuconazole, Fludioxonil + Sedaxen) showed differential effectiveness at various growth stages.
• Molecular tracking revealed higher infection potential of *Fusarium oxysporum* f. sp. *cepae* and identified inter-species interactions (antagonism/synergism).

Conclusions:

• Chemical treatments are effective against FBR pathogens, but phytotoxicity at higher doses necessitates dosage optimization.
• Combining specific fungicides can provide comprehensive protection throughout the onion lifecycle.
• qPCR offers a powerful tool for monitoring FBR pathogenesis and optimizing crop protection strategies.