First Report of Fruit Rot of Cherry and Its Control Using Fe2O3 Nanoparticles Synthesized in Calotropis procera

Spherical Fe2O3 nanoparticles inhibit the production of aflatoxins (B1 and B2) and regulate total soluble solids and titratable acidity of peach fruit

Aflatoxin is a group I carcinogen and causes significant public health and food safety risks, throughout the world. This study was carried out to assess the levels of aflatoxin contamination in diseased peach (Prunus persica L.) fruit and their control using myco-synthesized iron oxide nanoparticles (Fe2O3 NPs). Diseased peach fruit were diagnosed to be infected with Aspergillus flavus. The isolated pathogen was cultured under UV light (365 nm) and exposed to ammonium hydroxide (31 %) vapors, which confirmed its ability to produce aflatoxin. For the control of this disease, Fe2O3 NPs were synthesized in the filtrate of a biocontrol fungus (Trichoderma harzianum) and characterized before analyzing their potential in disease control. FTIR spectrum described the presence of capping and reducing agents (secondary amines, alcohol, alkyne and aromatic compounds) on the surface of Fe2O3 NPs. X-ray Diffraction (XRD) described the crystalline size (7.78), while the spherical shape of Fe2O3 NPs was described by the SEM analysis. The EDX spectrum indicated the successful formation of Fe2O3 NPs by showing strong signals of iron (74.38 %). All concentrations displayed mycelial growth inhibition, in vitro and the greatest growth reduction (65.4 %) was observed at 1 mg/ml concentration of NPs. At the same concentration of Fe2O3 NPs, significant control of fruit rot of peach was also observed, in vivo. Treatment of Fe2O3 NPs maintained higher soluble solids, sucrose, total sugar, ascorbic acid, titratable acidity and firmness of peach fruit. Diseased fruit were further investigated for the presence and detection of aflatoxins. All three methods viz. thin layer chromatography (TLC), enzyme-linked immunosorbent assay (ELISA) and high-performance liquid chromatography (HPLC) confirmed a higher production of aflatoxins in control plants, while this production was significantly reduced in Fe2O3 NPs-treated peach fruit.

Impact of bacterial synthesized nanoparticles on quality attributes and postharvest disease control efficacy of apricot and loquat

Postharvest fungal attacks on fruits such as apricots and loquats are common. Diseased fruit samples were collected from Murree's local fruit markets. The disease-causing pathogens were identified utilizing molecular, microscopic, and morphological characteristics. Alternaria alternata and Aspergillus niger were identified as the pathogens responsible for brown rot in loquat and black rot in apricot. To combat these fruit diseases, iron oxide (Fe2 O3 ) nanoparticles were synthesized using Bacillus subtilis and were characterized using various techniques. X-ray diffraction examination validated the size of iron oxide nanoparticles. The presence of several capping agents in the synthesized nanoparticles was confirmed by Fourier transform infrared analysis. Scanning electron microscopy revealed the spherical morphology of nanoparticles, whereas energy-dispersive X-ray proved the presence of different elemental compositions. After completing antifungal activities in vitro and in vivo, it was discovered that a nanoparticle concentration of 1.0 mg/mL efficiently suppressed the growth of fungal mycelia. Fungi growth was effectively inhibited in fruit samples treated with 1.0 mg/mL nanoparticles. The results of successful in vitro and in vivo antifungal activities imply that iron oxide (Fe2 O3 ) nanoparticles play an important role in ensuring fruit quality against pathogenic attacks. Bacterial-mediated iron oxide can be widely used because it is less expensive and less harmful to the environment than chemically manufactured fertilizers.

Effect of green Fe2O3 nanoparticles in controlling Fusarium fruit rot disease of loquat in Pakistan

The subtropical fruit known as the loquat is prized for both its flavour and its health benefits. The perishable nature of loquat makes it vulnerable to several biotic and abiotic stressors. During the previous growing season (March-April 2021), loquat in Islamabad showed signs of fruit rot. Loquat fruits bearing fruit rot symptoms were collected, and the pathogen that was causing the disease isolated and identified using its morphology, microscopic visualisation, and rRNA sequence. The pathogen that was isolated was identified as Fusarium oxysporum. Green synthesized metallic iron oxide nanoparticles (Fe2O3 NPs) were employed to treat fruit rot disease. Iron oxide nanoparticles were synthesized using a leaf extract of the Calotropis procera. Characterization of NPs was performed by different modern techniques. Fourier transform infrared spectroscopy (FTIR) determined the existence of stabilizing and reducing compounds like phenol, carbonyl compounds, and nitro compounds, on the surface of Fe2O3 NPs. X-ray diffraction (XRD) explained the crystalline nature and average size (~49 nm) of Fe2O3 NPs. Energy dispersive X-ray (EDX) exhibited Fe and O peaks, and scanning electron microscopy (SEM) confirmed the smaller size and spherical shape of Fe2O3 NPs. Following both in vitro and in vivo approaches, the antifungal potential of Fe2O3 NPs was determined, at different concentrations. The results of both in vitro and in vivo analyses depicted that the maximum fungal growth inhibition was observed at concentration of 1.0 mg/mL of Fe2O3 NPs. Successful mycelial growth inhibition and significantly reduced disease incidence suggest the future application of Fe2O3 NPs as bio fungicides to control fruit rot disease of loquat.

Bioinspired Green Synthesis of Bimetallic Iron and Zinc Oxide Nanoparticles Using Mushroom Extract and Use against Aspergillus niger; The Most Devastating Fungi of the Green World

In the current study, a macro fungus was collected and identified by using morphological and molecular tools to study the ITS region, which has been described as a universal barcode marker during molecular investigation for the identification of fungi. Based on morphology and molecular evidence, the collected fungus was identified as Daedalea Mushroom. The identified fungus was used for the synthesis of Iron and ZnO nanoparticles as an eco-friendly agent for nanoparticle synthesis. The synthesized nanoparticles were confirmed by, Fourier transfer infrared spectroscopy analysis (FTIR), X-ray diffraction analysis (XRD), energy dispersive X-ray analysis (EDX), and scanning electron microscopy analysis (SEM). All these characterizations revealed the synthesis of Iron and ZnO NPs with an irregular shape and a size of 16.8 nm. The zinc oxide nanoparticles had a size in the range of 18.53 nm. Daedalea Mushroom was used for the first time to synthesize Iron and zinc nanoparticles. The mycosynthesized Iron and ZnO NPs were assessed as control agents at various dosage rates against the pathogenic fungus Aspergillus niger, which was isolated from an apple and identified using its morphology. At higher concentrations (0.75 mg/mL), the iron nanoparticles inhibited fungal growth by 72%, whereas at lower concentrations (0.25 mg/mL), they inhibited fungal growth by 60%. ZnO NPs showed good antifungal activity at different concentrations including growth inhibition at 0.25 mg/mL (88%), 1.0 mg/mL (68%), 0.75 mg/mL (75%), and 0.5 mg/mL (70%) concentrations of ZnO NPs. However, the maximum growth inhibition of ZnO NPs was observed at 0.25 mg/mL (88%) concentration and minimum growth inhibition at 0.1 mg/mL (22%). The current study concludes that Daedalea Mushroom works as a novel and eco-friendly source for the synthesis of Iron and ZnO NPs with prominent antifungal activities that can be further applied in different fields.