Colletotrichum fioriniae, causal agent of postharvest avocado fruit rot in Southern Italy

Colletotrichum includes pathogens affecting different plant hosts in tropical, subtropical, and temperate regions. Anthracnose caused by these pathogens is a prevalent and severe postharvest disease of tropical fruits, including avocado. In 2021, avocado fruit with typical anthracnose symptoms was found during storage, and on very ripe fruit, in Caserta, Campania region, Italy. Avocado cultivation and production is increasing in this region, so the etiology of this disease was examined. Molecular and phylogenetic analyses on four genomic loci (ITS, gapdh, act and tub2) combined with morphology identified selected representative isolates as Colletotrichum fioriniae, in the C. acutatum species complex. Pathogenicity of isolates was confirmed by inoculating them on healthy avocado fruit (cv. Pinkerton). This is the first report of C. fioriniae causing post-harvest fruit rot on avocado in Italy. This pathogen merits further epidemiological and ecological investigations, to provide basic knowledge supporting development of management of its spread and mitigating possible impacts on avocado production.