FIG 9.

Verticillium dahliae VdGAL4 was a virulence factor in cotton. (A) Cotton seedlings (Gossypium hirsutum cv. Jimian11) were mock inoculated (Mock) or inoculated with WT, ΔVdGAL4, and C-ΔVdGAL4 strains and photographed at 26 days postinoculation. (B) V. dahliae from the cotton stem was reisolated on PDA medium at 25°C for 5 days. (C) Observation of browning of vascular bundle in the longitudinal section of stem of cotton seedlings. (D) Disease index of cotton seedlings inoculated with all tested strains at 14, 20, and 26 days postinoculation. (E) Colonization, by RT-qPCR, of V. dahliae in cotton stem after 26 days of infection. The error bar represents standard error of the mean. *, P < 0.05; **, P < 0.01.