A novel race of Fusarium oxysporum f. sp. apii in Michigan affecting celery

Eleven Fusarium oxysporum f. sp. apii (Foa) isolates were collected from commercial celery fields in Michigan from 2018 to 2021 and sequenced at the Michigan State University Genomics Core. The run was conducted on a NovaSeq 6000 S1 flow cell in a 2x150bp paired-end format. Two isolates (F19-32 & F18-33) were positive for Foa race 2 specific markers, while the other nine isolates were of a single multilocus genotype identical to the Foa race 1 reference. Despite this similarity, this group is genetically distinct from Foa race 1 and all other known Foa races. Six isolates (F19-08, F19-01, F19-09, F19-28, F18-05, and F19-05) were shown to be pathogenic on modern race 2- resistant cultivars and support the designation of a novel race, proposed as Foa race 5.