Figure 3

Enzyme activities of SOD, POD, PPO and PAL in tomato roots on different days after inoculation with V. dahliae.
(A) SOD activity. (B) POD activity. (C) PPO activity. (D) PAL activity. TM indicates tomato monoculture; TC indicates tomato grown with potato onions. The data are presented as the means ± SD, n = 3. The asterisk (*) indicates a significant difference between two groups of mean values (p <0.05).