Miniature and Ilona roses grown on medium enriched with FeO nanoparticles have a significant improvement in growth parameters

Iron is one of the important essential elements for the nutrition of almost all living organisms. This element plays a crucial role in various processes in plant cells due to its ability to gain and lose electrons. This element is involved in several oxidation–reduction reactions and is necessary for several processes in plant cells, such as photosynthesis and respiration. Iron is an important minor plant nutrient that is used in different media of in vitro cultures. In this study, the nodal segments of two rose cultivars, Miniature and Ilona, were cultured on Murashige and Skoog (MS) medium enriched with various iron sources, including iron-ethylene diamine tetraacetic acid (Fe-EDTA), iron-ethylene diamine-N,Nʹ-bis (hydroxy phenyl), acetic acid (Fe-EDDHA), FeO nanoparticles (FeO NPs), and FeO nanoparticles coated with polyethylene glycol (FeO@PEG NPs). Iron-free MS culture medium was used as the control. After 21 d, shoot and root length, the number of axillary shoots and leaves, leaf chlorosis, shoot and root fresh and dry weights, leaf area, chlorophyll a, chlorophyll b, and total chlorophyll were measured and analyzed. The results showed that all growth parameters were improved for both Ilona and Miniature roses grown on MS medium with FeO NPs while the roses grown on MS medium with FeO@PEG NPs were similar to those grown on MS medium with Fe-EDDHA. Overall, the use of FeO NPs represents a promising approach for improving all growth parameters in rose cultivars.