The effect of nano-iron oxide on growth, physiology, and callogenesis in pepper in vitro

. The aim of this research was to study the effect of iron oxide nanoparticles (FeO NPs) on the growth, differentiation, anatomy, and physiology of pepper ( Capsicum annuum L.) on the basis of a completely randomized design in vitro condition. Seedlings were cultured in MS medium containing four concentrations of FeO NPs (0, 1, 10, and 20 mgl -1 ). Also, the effect of the different concentrations of FeO NPs on callus formation under two various hormone conditions (0.5mgl -1 2,4D+0.5 mgl -1 BAP or 0.5 mgl -1 BAP+1 mgl -1 Kin) were assessed. The results showed that the application of FeO NPs significantly increased biomass accumulation in both roots and shoots. Moreover, FeO NPs enhanced the concentrations of photosynthesis pigments (chllrophyll a , chlorophyll b , and carotenoids). The presence of FeO NPs in culture medium affected callus formation in a hormone-dependent manner. Different concentration of FeO NPs induced the callus formation under 2, 4-D and BAP treatments. However, it did not significantly increase callus formation under the kinitin and 2,4-D. The findings of this research indicated that the application of FeO NPs at optimized doses may improve plant production, especially in vitro condition.