Diversity, Taxonomy, and Pathogenicity of Members of Fusarium tricinctum Species Complex Associated with Wild Rosaceae Fruits

This study investigated Fusarium species associated with seven wild relatives of four economically important Rosaceae fruits in Sichuan Province, China, including wild strawberry (Fragaria sp. and Potentilla indica), wild raspberry (Rubus rosaefolius), wild cherry (Prunus sp., Maddenia sp. and Prunus leveilleana), and wild apple (Malus kansuensis). Based on multi-gene phylogenetic analyses and morphological characteristics, seven Fusarium species within the Fusarium tricinctum species complex (FTSC) were identified. Among these, four are described as new species (F. fragariae, F. potentillae, F. pruni and F. fructicola), while the remaining three represent new host records (F. avenaceum, F. diversisporum and F. paeoniae). In addition, phylogenetic and morphological evidence indicated that F. rosiradicicola is conspecific with F. diversisporum. Prioritizing the oldest epithet, we synonymized F. rosiradicicola under F. diversisporum. The pathogenicity of the isolates was evaluated on both their wild hosts and the corresponding cultivated fruits using detached, wound-inoculated assays. All tested isolates produced symptoms, showing pathogenic potential under experimental conditions. This study shows that selected wild Rosaceae fruits harbor several members of the FTSC and provides preliminary evidence of cross-host susceptibility under experimental conditions. However, further field-based investigations and non-wound inoculation studies are required to clarify their ecological roles, natural host susceptibility, and potential relevance in cultivated systems.