FIG 6.

Antibiotic activities of PCA, PCN, and 2-OH-PHZ against three potato pathogens. Phenazine compounds dissolved in DMSO were added to culture media inoculated with one of the three potato pathogens: Phytophthora infestans (A), Streptomyces scabies (B), and Verticillium dahliae (C). The colors correspond to PCA (white), PCN (gray), and 2-OH-PHZ (black). Statistical analyses (Kruskal-Wallis, followed by post hoc tests) were conducted to compare each concentration, and significant differences (P < 0.05) are indicated with different lowercase letters. Relative inhibitions were not compared across different concentrations or pathogens. Error bars represent the standard errors.