Effects of arbuscular mycorrhizal fungi and salicylic acid on plant growth and the activity of antioxidative enzymes against wilt disease caused by Verticillium dahliae in pepper

This study was carried out to address the effects of arbuscular mycorrhizal fungi (AMF) and salicylic acid (SA) on plant growth and the activity of antioxidative enzymes against wilt disease caused by Verticillium dahliae Kleb. (Vd) in pepper. AMF (2.5 g) applications positively affected the development of pepper plants, although SA alone did not cause a significant effect. The combined application of SA and AMF significantly increased shoot length (7.5%) except for the other plant growth parameters. SA combined with AMF suppressed wilting by 42.5% and vascular discoloration by 69.4%. The gallic acid content in pepper plants varied depending on the applications and time after treatment; SA and AMF applications increased gallic acid content compared with the control. These treatments also increased activity of antioxidative enzymes superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT) in pepper plants compared to the control.