First Report of Fusarium equiseti Causing Postharvest Fruit Rot of Avocado in Türkiye

Abstract

In September 2024, postharvest fruit rot, including stem-end rot, was observed on avocado in the Altınordu district of Ordu province, located in the Eastern Black Sea Region of Türkiye. A market survey revealed that 5% of fruit exhibited fruit rot symptoms, a subset of which displayed stem-end rot symptoms, including brown to black lesions extending into the mesocarp, shrivelling and fungal mycelium growth. Fusarium equiseti was identified as the causal agent through morphological characterisation and molecular analysis using PCR amplification and sequencing of translation elongation factor 1-alpha (tef1) and RNA polymerase II second largest subunit (rpb2) gene sequences, including phylogenetic analysis. Artificial inoculation and subsequent re-isolation confirmed Koch's postulates, verifying F. equiseti as the causal pathogen. This is the first report of F. equiseti causing both fruit rot and stem-end rot on avocado in Türkiye, highlighting the need for improved postharvest disease management strategies to reduce economic losses in Türkiye's avocado industry.