The effect of Arbuscular Mycorrhizal fungal species Funneliformis mosseae and biochar against Verticillium dahliae in pepper plants under salt stress

Both biotic and abiotic stress factors play an important role in reducing the growth and productivity of many crops. In this study, the effects of arbuscular mycorrhizal (AM) fungi and biochar (Bc) were investigated against Verticillium dahliae (Vd) disease in pepper plants grown under salt stress. These effects were evaluated on enzyme activities, salt tolerance, disease severity, plant growth and physiological characteristics. In this study, pepper was treated with 2% biochar, Funneliformis mosseae (Fm), Vd and different concentrations of salt (0 mM, 50 mM, 100 mM, 150 mM). The interaction of Fm and 2% Bc significantly increased the morphological parameters of the plant and the plant tolerated salt and Vd under combined high stress conditions of biotic (Vd) and abiotic (salt) stresses. It was also shown that Fm had a different effect than Bc on the membrane injury index (MII; %) and had a significant effect on leaf relative water content (LRWC; %). In addition, Vd increased mycorrhizal reliance, with the higher spore density of AMF higher disease severity observed in treatments involving Fm and Fm + Bc. Furthermore, phenol and antioxidant values were altered in Vd treatments, while Fm decreased CAT enzyme activation. Therefore, this study supports that AMF + biochar used in sustainable agriculture increases plant resistance to the soil pathogen (V. dahliae) and the salt stresses.