Effect of vermicompost and mycorrhiza fungi on yield and growth of milk thistle and antioxidant system activity.

In this study, the effect of vermicompost and mycorrhizal fungi was investigated on growth, yield, chlorophyll pigments, leaf antioxidant enzymes, and seed silibinin content of Silybum marianum, milk thistle. The seeds were inoculated by two species of mycorrhiza fungi, Glomus mosseae and G. intraradices, and plants were irrigated and treated with 0, 25, 50, and 75% vermicompost after culturing. The treated plants were then compared to control plants in a greenhouse experiment. The results showed that growth parameters including leaf area, and plant height and yield significantly increased in mycorrhiza fungi treated plants especially along with 75 % vermicompost treatment. The effects of symbiotic relationship between milk thistle and G. intraradices were more pronounced than G. mosseae. Moreover, combination of mycorrhiza and vermicompost increased the photosynthetic pigments chlorophyll (a), chlorophyll (b), total chlorophyll, and carotenoid.  Also, a significant decrease was observed in activities of peroxidase, superoxide dismutase, and catalase after vermicompost and mycorrhiza treatment. The results showed that silibinin decreased significantly in vermicompost application.