Evaluate effect of mycorrhizal, zinc and iron oxide on root growth, antioxidant enzyme activities, and mineral elements in sorghum (Sorghum bicolor)

Zinc (Zn) and Iron (Fe) are essential micronutrients that play crucial role on crop plants. Adequate amount of these elements is required for metabolic synthesis, enzyme activity and improvement of overall yield. Mycorrhizal also enhance the uptake and facilitate absorption of water and essential elements in crop plants. This study aimed to evaluate the effect of foliar application of Zn and iron Fe oxides in both normal (2 g L-1) and nano form (1.5 g L-1) combined with inoculation mycorrhiza (Funneliformis mosseae) on root growth and some physiological characteristics in sorghum. Zn and Fe oxides in both normal and nano forms, increased the root growth. Normal form of Fe and Zn oxides showed the greater effect on this trait. Inoculation with Funneliformis mosseae, increased root and shoot dry weight 9.6% and enhanced root length and volume 12.6%. Moreover, Zn and Fe oxides treatments increased the activity of antioxidant enzymes such as guaiacol peroxidase (GPX), ascorbate peroxidase (APX) and catalase (CAT) in leaf tissues. No significant difference was observed between the nano and normal forms regarding these antioxidant enzyme activities. Funneliformis mosseae as well as Fe and Zn oxide, increased the concentration of Fe and Zn in the leaves. The highest Fe and Zn concentrations were obtained under foliar application of Zn and Fe oxides in normal form. The results demonstrated that, under symbiosis with the Funneliformis mosseae, foliar application of Fe and Zn oxides in their normal form has a greater effect on root growth and enzyme activities in sorghum plants compared to the nano form.