# First Report of Coffea arabica Fruit Rot Disease Caused by Fusarium coffeibaccae in China

## TL;DR

A new coffee fruit rot disease caused by Fusarium coffeibaccae was first identified in China, threatening the coffee industry there.

## Contribution

This is the first report of Fusarium coffeibaccae causing fruit rot in Coffea arabica in China.

## Key findings

- Fusarium coffeibaccae was identified as the causal agent of fruit rot in Coffea arabica in Yunnan, China.
- Koch’s postulates were confirmed, showing the fungus causes typical rot symptoms on coffee fruits.
- Genetic sequences of the fungus were deposited in GenBank for future reference and study.

## Abstract

Coffea arabica, a popular beverage ingredient, is prized for its rich chemical composition, which has demonstrated significant positive effects in terms of antioxidant, anti-inflammatory, neuroprotective, and metabolic health. In November 2024, fruit rot with a 15% incidence was observed on C. arabica in Menglian city, Yunnan province, China. Symptoms began as irregular black spots that turned necrotic, wrinkled, and cracked. Fungal isolates from lesions showed morphological characteristics consistent with Fusarium coffeibaccae. Morphological data were supplemented with phylogenetic analyses based on three loci (ITS, TEF1-α, RPB2), and sequences were deposited in GenBank as for ITS (PV211189 and PV211190), TEF1-α (PQ867811 and PQ867812), and RPB2 (PV261064 and PV261065). Koch’s postulates were fulfilled on attached fruits. After 17 days at 25 °C with 70% humidity, typical rot symptoms appeared on inoculated fruits, while controls remained symptom-free. This is the first report of C. arabica fruit rot caused by F. coffeibaccae in China. This study aims to identify the aetiological agent of recently observed coffee fruit rot in Yunnan and to characterize F. coffeibaccae. It provides the first baseline data for targeted monitoring and sustainable control of F. coffeibaccae-mediated fruit rot in China’s expanding coffee sector.