FIG. 5.

Effects of fungicides on the mycelium radial growth and conidia germination rate of the A. brassicicola wild-type isolate and AbNIK1-null mutants. (A) In vitro growth tests were carried out on potato dextrose agar medium supplemented with iprodione, fludioxonil, or ambruticin at 0.1, 1, and 10 mg/liter. Growth of the Abra43 and nik1Δ3 strains was scored after 4 days of incubation at 25°C. (B) Germination rates were estimated by counting, under a microscope, the number of germinated conidia after incubation for 24 h at 25°C in the presence of iprodione, fludioxonil, and ambruticin at 0.01, 0.1, 1, 10, and 100 mg/liter. The results are expressed as the percentage of inhibition in treated samples compared to the control without fungicide. Values are the means of three replicates; error bars indicate standard deviations. White bars, Abra43; striped bars, Abra43M; light gray bars, nik1Δ1; medium gray bars, nik1Δ2; black bars, nik1Δ3.