Defense responses of apple treated with the yeast Pichia guilliermondii and silicon against Penicillium expansum

In this study variation of Peroxidase activity and phenolic compounds were studied after treating with Pichia guilliermondii (A6) and silicon (Si) and inoculation with Penicillium expansum (F1). The samples were taken in zero, second, fourth, sixth and eighth days after pathogen inoculation. The results showed that Peroxidase activity increased during these days and achieved the highest activity in sixth and eighth days. These results indicated that the phenolic compounds were in maximum amount in the second day after pathogen inoculation. These findings emphasized that increase in peroxidase activity and phenolic compounds could be the reason for induction of resistance in apple fruits.