Effect of nanocellulose-assisted green-synthesized iron nanoparticles and conventional sources of Fe on pot marigold plants symbiotically with arbuscular mycorrhizal fungus (Funneliformis mosseae).

The objective of this study was to investigate the effect of nanocellulose-assisted green-synthesized iron nanoparticles (FeNPs) and conventional sources of Fe on pot marigold (Calendula officinalis L.) plants symbiotically with arbuscular mycorrhizal (AM). Pot marigold plants were inoculated with Funneliformis mosseae in addition to applying ferrous sulfate, FeNPs, and Fe-EDDHA at a rate of 10 mg Fe/kg soil, which follows the recommended rates of fertilizer. Their effects on plant growth, morphology, and physiological parameters were to be compared in the experiment. According to the findings, FeNPs significantly increased plant height, mean stem length, flower number, and total flower lifespan, especially when used with AMF. Most notably, this treatment produced the highest total chlorophyll content (6.62 mg/g FW), active iron in leaves (10 µg/g FW), essential oil (5.75%), mean number of leaves per plant (26.25), number of flowers per plant (6.5), and overall flower lifespan (92.75 days). It also produced superior mycorrhizal root colonization (52.47%). However, because of its lower uptake efficiency and rapid oxidation, ferrous sulfate showed limited performance. By enhancing iron bioavailability, the FeNPs promoted more effective metabolic activity and nutrient absorption. These results demonstrate the advantage of producing FeNPs as a bio-sustainable and biocompatible alternative for synthetic chelates, thus providing an interesting way to improve crop growth promotion in mycorrhizal cropping systems.