FIG 1.

The phenotypes of ΔVdSsk2 and ΔVdSte11 strains of Verticillium dahliae in axenic culture. (A, top) Colony morphology of XS11, ΔVdSsk2, and ΔVdSte11 strains, and the respective complemented strains were incubated on BM for 7 days. The aerial hyphal growth of the strains was observed after growth. (Bottom) Vertical dissection of the colonies. Bars = 1 cm. (B) Strains were cultured in yeast extract peptone-dextrose liquid medium at 25°C for 24 h, 48 h, and 7 days (d). Germination of conidia and filamentous branching were imaged with a compound microscope. All cultures were inoculated with the same amount of spores (10⁶ conidia/ml). Bars = 0.5 cm. (C) Strains were cultured on PDA for 7 days. Germ tubes from germinated conidia and hyphae were stained with 10 mg/ml CFW for 5 min. The CFW signal was imaged by fluorescence microscopy, and the CFW signal in the hyphal septum was quantified separately. Bar = 10 μm. (D) Number of hyphal septum calculated in the single hypha in panel C. Values are means plus standard deviations (error bars) from three replicates. Values that are significantly different (P < 0.01) from the value for the wild-type strain XS11 are indicated by two asterisks.