Is the host range of Alternaria dauci restricted to carrot?

The host range of Alternaria dauci was investigated in a greenhouse. Two strains were inoculated onto nine cultivated Apiaceae species, two wild Daucus species and six cultivated non-Apiaceae species representing six botanic families. Lesions of various intensities were observed on all dicot species, but no symptoms developed on the two monocots studied. Typical A. dauci conidia were observed after in vitro incubation of necrotic leaves. Fungal strains were isolated from lesions and A. dauci was diagnosed on the basis of conidium morphology and specific conventional PCR findings. Genotyping of individual isolates performed with microsatellite markers confirmed the presence of the inoculated strain. Our results strongly suggest that species other than carrot can be alternative hosts. Those results are important to consider for a better management of Alternaria leaf blight in carrot fields.