Which Fusarium species cause crown rot on banana fruit in the Hawaiian Islands?

The Hawaii archipelago represents a unique environment due to geographic isolation and, for banana cultivation, the unique use of a diverse set of local varieties. The study aimed to assess which Fusarium species are associated with Fusarium crown rot disease of banana fruit in Hawaiian Islands by sampling local and international varieties both in production areas as well as in local markets. A total of 41 banana fruits belonging to 10 varieties showing typical crown rot symptoms collected in plantations of Oahu and Manoa islands, as well as in supermarkets and local farmers' markets of the two islands, were collected during June/July 2024. A total of 18 Fusarium colonies, isolated using Komada medium, were obtained. Single spore isolation and RPB2 and EF sequencing led to the identification of the main Fusarium species/species complexes. The most abundant group of isolates belonged to FIESC (n=12), followed by F. petrophillum (n=2), FOSC (n=1) and F. verticillioides (n=1). Three whole genomes were obtained to serve as references for the island’s local Fusarium populations. No F. musae was detected on the Hawaiian Islands during this survey.