Genomic insights into Fusarium oxysporum f. sp. cyclaminis: endorsing the causal agent of Fusarium wilt on cyclamen in Brazil

Abstract

In 2023, a severe outbreak led to a 70% mortality rate among Cyclamen persicum plants in Holambra, São Paulo, prompting an investigation to identify the causal agent. Symptomatic plants were sampled, and the fungus, designated CMAA 1919, was isolated and identified through morphological analysis. Pathogenicity was verified via Koch’s postulates, with inoculated plants replicating wilt symptoms. To support genomic characterization of the pathogen, whole-genome sequencing was conducted using the Illumina platform. Genomic DNA was extracted, sequenced, and processed, resulting in a 48.9 Mb genome with 200x coverage and 97.5% completeness. Phylogenetic analysis positioned CMAA 1919 within a Fusarium cluster, confirming its closest relation to Fusarium oxysporum strain Fo47 (99.07% genomic similarity) and other pathogenic strains. This study presents the first genomic and morphological description of Fusarium oxysporum f. sp. cyclaminis (CMAA 1919), the causative agent of Fusarium wilt in cyclamen in Brazil.