Host ranges of North American isolates of Penicillium causing blue mold of bulb crops

- Penicillium isolates in series Corymbifera were identified from North American Sources.
- Isolates representative of species in Corymbifera differed in host range.
- Management implications are discussed.

Single isolates of four Penicillium species belonging to series Corymbifera (Penicillium allii, Penicillium hirsutum, Penicillium tulipae, Penicillium venetum) plus an isolate of Penicillium polonicum, all from North American sources, were inoculated individually into Crocus sativus (crocus), Allium sativum (garlic), Allium cepa (onion), Allium stipitatum (ornamental onion), Iris hollandica (iris), Ornithogalum umbellatum (grass lily), and varieties of Gladiolus (gladiolus), Tulipa (tulip) and Narcissus (daffodil). All isolates were pathogenic to garlic and onion (but none to ornamental onion), and all but P. polonicum to Tulipa, although virulence varied considerably. Additionally, P. hirsutum was pathogenic to Crocus, Gladiolus and Iris; P. tulipae to Narcissus, Crocus, Ornithogalum and Iris; P. venetum to Gladiolus, Ornithogalum and Iris; and P. polonicum to Iris. Nomenclature and taxonomy of series Corymbifera are summarized, the above results compared to similar investigations in Europe, and management implications provided.