title: Induction and Characterization of Penicillium caseicolum Mutants Resistant to Ergosterol Biosynthesis Inhibitors.
abstract: The isolation of Penicillium caseicolum mutants resistant to different fungicides which inhibit ergosterol biosynthesis is reported. Mutational frequencies for resistance were high (3 x 10 to 3 x 10). The levels of resistance toward the inhibitors of sterol C-14 demethylation were always low (<10), whereas high values were obtained with mutants resistant to inhibitors of sterol Delta14 reduction or Delta8-->Delta7 isomerization, or both. Generally, there was a positive cross-resistance between fungicides showing the same biochemical mode of action but not between compounds of two different groups. Mycelial growth rate and sporulation were tested; several mutants were not affected for these characteristics. We conclude that resistance to ergosterol biosynthesis inhibitors may be used as a good marker for genetic studies through protoplast fusion.
authors.affiliation: Laboratoire de Cryptogamie, Université de Paris-Sud, Centre d'Orsay, Bâtiment 400, 91405 Orsay Cedex, and Laboratoire de Phytopharmacie, Institut National de la Recherche Agronomique, 78000 Versailles, France.
authors.forename: A
authors.initials: A
authors.lastname: de Falandre
authors.forename: I
authors.initials: I
authors.lastname: Bouvier-Fourcade
authors.forename: J M
authors.initials: JM
authors.lastname: Seng
authors.forename: P
authors.initials: P
authors.lastname: Leroux