Germination and Infectious Potential of Microconidia of Sclerotium cepivorum

Observation with the scanning electron microscope showed that microconidia of Sclerotium cepivorum are able to germinate on onion plants. A young hypha penetrated the plant cuticle. Cytochemical techniques gave evidence of phenoloxydase and esterase activities in microconidia and thus confirmed their infectious potential. Massive production of microconidia was induced by immersion of the fungus in water. These elements suggest that in high moisture conditions microconidia of S. cepivorum might play a crucial role in survival and dissemination of the fungus.