Scanning electron microscopy of bio-fabricated Fe(2) O(3) nanoparticles and their application to control brown rot of citrus.

Citrus is the leading fruit crop of Pakistan and exported to different parts of the world. Due to suitable weather condition, this crop is affected by different biotic factors which seriously deteriorate its quality and quantity. During the months of November 2018 to January 2019, citrus brown rot symptoms were recurrently observed on sweet oranges in National Agricultural Research Centre (NARC), Islamabad. Causal agent of citrus brown rot was isolated, characterized, and identified as Fusarium oxysporum. For environment-friendly control of this disease, leaf extract of Azadirachta indica was used for the green synthesis of iron oxide (Fe2 O3 ) nanoparticles. These nanoparticles were characterized before their application for disease control. Fourier transform infrared spectroscopy (FTIR) of these synthesized nanoparticles described the presence of stabilizing and reducing compounds like alcohol, phenol, carboxylic acid, and alkaline and aromatic compounds. X-Ray diffraction (XRD) analysis revealed the crystalline nature and size (24 nm) of these nanoparticles. Energy dispersive X-Ray (EDX) analysis elaborated the presence of major elements in the samples. Scanning electron microscopy (SEM) confirmed the spinal shaped morphology of prepared nanoparticles. Successfully synthesized nanoparticles were evaluated for their antifungal potential. Different concentrations of Fe2 O3 nanoparticles were used and maximum mycelial inhibition was observed at 1.0 mg/ml concentration. On the basis of these findings, it could be concluded that Fe2 O3 nanoparticles, synthesized in the leaf extract of A. indica, can be successfully used for the control of brown rot of sweet oranges.

Ali M ，Haroon U ，Khizar M ，Chaudhary HJ ，Hussain Munis MF ... -  《-》

Effect of green Fe(2)O(3) 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.

Niazi F ，Ali M ，Haroon U ，Farhana ，Kamal A ，Rashid T ，Anwar F ，Nawab R ，Chaudhary HJ ，Munis MFH ... -  《-》

Antifungal activity of Zinc nitrate derived nano Zno fungicide synthesized from Trachyspermum ammi to control fruit rot disease of grapefruit.

Grapefruit (Citrus paradisi) is a widely grown citrus and its fruit is affected by a variety of biotic and abiotic stress. Keeping in view the hazardous effects of synthetic fungicides, the recent trend is shifting towards safer and eco-friendly control of fruit diseases. The present study was aimed to diagnose the fruit rot disease of grapefruit and its control by using zinc oxide green nanoparticles (ZnO NPs). Fruit rot symptoms were observed in various grapefruit growing sites of Pakistan. Diseased samples were collected, and the disease-causing pathogen was isolated. Following Koch's postulates, the isolated pathogen was identified as Rhizoctonia solani. For eco-friendly control of this disease, ZnO NPs were prepared in the seed extract of Trachyspermum ammi and characterized. Fourier transform infrared spectroscopy (FTIR) of these NPs described the presence of stabilizing and reducing compounds such as phenols, aldehyde and vinyl ether, especially thymol (phenol). X-ray diffraction (XRD) analysis revealed their crystalline nature and size (48.52 nm). Energy dispersive X-ray (EDX) analysis elaborated the presence of major elements in the samples, while scanning electron microscopy (SEM) confirmed the morphology of bio fabricated NPs. ZnO NPs exhibited very good anti-fungal activity and the most significant fungal growth inhibition was observed at 1.0 mg/ml concentration of green NPs, in vitro and in vivo. These findings described that the bioactive constituents of T. ammi seed extract can effectively reduce and stabilize ZnO NPs. It is a cost-effective method to successfully control the fruit rot disease of grapefruit.

Ali M ，Wang X ，Haroon U ，Chaudhary HJ ，Kamal A ，Ali Q ，Saleem MH ，Usman K ，Alatawi A ，Ali S ，Hussain Munis MF ... -  《-》

Mycosynthesized Fe(2) O(3) nanoparticles diminish brown rot of apple whilst maintaining composition and pertinent organoleptic properties.

Iron oxide nanoparticles (Fe2 O3 NPs) were mycosynthesized using Trichoderma harzianum and applied to control brown rot of apple. The influence of Fe2 O3 NPs on the quality of fruit was also studied. Diseased apple fruits with brown rot symptoms were collected, and the disease-causing pathogen was isolated and identified as Fusarium oxysporum. To control this disease, mycosynthesis of Fe2 O3 NPs was executed using T. harzianum. FTIR spectroscopy revealed the occurrence of stabilizing and reducing agents on NPs. X-ray diffraction (XRD) analysis determined their average size (17.78 nm) and crystalline nature. Energy-dispersive X-ray (EDX) showed strong signals of iron, and scanning electron microscopy (SEM) displayed a high degree of polydispersity of synthesized NPs. Foliar application of NPs significantly reduced brown rot and helped fruits to maintain biochemical and organoleptic properties. Firmness and higher percentage of soluble solids, sugars and ascorbic acid depicted its good quality. Environment-friendly mycosynthesized Fe2 O3 NPs can be effectively used to control brown rot of apple. Trichoderma harzianum is a famous biocontrol agent, and the synthesis of NPs in its extract is an exciting avenue to control fungal diseases. Due to its nontoxic nature to human gut, it can be applied on all edible fruits.

Akbar M ，Haroon U ，Ali M ，Tahir K ，Chaudhary HJ ，Munis MFH ... -  《-》

Application of phyto-fabricated zinc oxide nanoparticles to diminish brown spot of pear whilst maintaining its quality.

Pyrus communis is a common fruit of temperate region, its domestication and origin is at two different points, Asia and China. Pear fruits bearing brown spot symptoms were picked, and pathogen was isolated and poured on Potato Dextrose Agar (PDA) media. On basis of molecular and molecular analyses, this isolated pathogen was identified as Alternaria alternata. Zinc oxide nanoparticles (ZnO NPs) were prepared from Theveti peruviana leaf extract and were characterized through various techniques Fourier Transform Infrared Spectroscopy (FTIR) analysis of prepared ZnO NPs depicted the presence of agents responsible for stabilization and reduction such as alkenes, alkynes, nitro compounds, alkyl halides, aromatic compounds and aliphatic amines. X-ray diffraction (XRD) analysis confirmed the size (27 nm) and crystalline nature of ZnO NPs. Scanning electron microscopy (SEM) depicted the irregular shape of the prepared ZnO NPs. Mass percentage of zinc (79.84%) and oxygen (20.16%) was depicted using Energy Dispersive X-Ray (EDX) analysis. The in vitro and in vivo antifungal activity (A.F) of prepared NPs against A. alternata was confirmed by poisoned food technique and wound inoculation method. On the basis of which it was concluded that 1.0 mg/mL concentration of ZnO NPs could effectively inhibit A. alteranata growth and minimize the risk of brown spot of pear. SEM images of A. alternata under 1 mg/mL NPs showed the deformation in morphology of A. alternata. ZnO NPs also aided in the preservation of its various organoleptic and biochemical properties. The high percentage of soluble solids, firmness, ascorbic acid and sugars demonstrated its high quality. It has been concluded that 1 mg/mL ZnO NPs can effectively control brown spot of pear while maintaining its quality. In addition, the method might be applied to control emerging diseases in an ecofriendly way to meet the global food demand. RESEARCH HIGHLIGHTS: Isolation and characterization of pathogen causing brown spot in pear. Pathogenicity of A. alternata was checked on healthy fruits. Thevetia peruviana leaf extract was used for the synthesis, characterization and antifungal assay of ZnO Nanoparticles. Green synthesized nanoparticles can be economically effective alternative fungicide for the large scale in agriculture fields.

Jabeen H ，Haroon U ，Bilal A ，Anjum L ，Kamal A ，Bibi H ，Anar M ，Ahmed J ，Farhana ，Saleem H ，Akbar M ，Munis MFH ... -  《-》