ABSTRACT
BACKGROUND: Most microorganisms that cause food decay and the lower the shelf life of foods are fungi. Nanotechnologies can combat various diseases and deal with the application of nanomaterial to target cells or tissues. In this study selenium nanoparticles (Se-NPs) were synthesized using ascorbic acid and characterized by ultraviolet-visible spectroscopy, transmission electron microscopy (TEM), X-ray diffraction and zeta potential. The different concentrations of As/Se-NPs were tested against various fungi, including Alternaria linicola, Alternaria padwickii, Botrytis cinerea, Bipolaris sp., Cephalosporium acremonium, Fusarium moniliform and Fusarium semitectum. This study tested the influence of coated As/Se-NPs on healthy strawberry fruits and those infected with Botrytis cinerea during 16 days of storage, with regard to shelf life, decay percentage, weight loss, total titratable acidity percentage, total soluble solids content (TSS) and anthocyanin content. RESULTS: Energy-dispersive X-ray analysis showed only two elements: selenium and oxygen. TEM images showed that the nanoparticles ranged in size between 26 to 39 nm and were rhombohedral in shape. Se-NPs showed antifungal activity against all tested fungi, the most effective being against Botrytis cinerea, Cephalosporium acremonium and Fusarium semitectum. During storage periods of strawberries fruits coated with As/Se-NPs, the shelf life was increased, and the number of decaying fruits was less than in control (uncoated) and coated infected fruits. The decline in weight loss was lower in coated fruits than in control fruits. CONCLUSION: These findings demonstrated that As/Se-NPs could effectively maintain the postharvest quality of strawberries, even when the fruit was infected with B. cinerea. © 2024 Society of Chemical Industry.
ABSTRACT
Fungal diseases have always been a major problem for cantaloupe crops; however, synthetic fungicides are hazardous to humans and the environment. Consequently, a feasible alternative to fungicides without side effects could be by using bio agents and naturally occurring plants with antibacterial potential. This study has achieved a novel procedure for managing wilt and root rot diseases by potentially using Trichoderma sp. culture filtrates in consortium with plant extract of Calotropis procera, Rhizoctonia solani, Fusarium oxysporum, and Pythium ultimum, which were isolated from infected cantaloupe roots with identified root rot symptoms. The antagonistic activity of four Trichoderma isolates and analysis of antibiotics and filtrate enzymes of the most active Trichoderma isolate were determined as well as phytochemical analysis of C. procera plant extract using HPLC-UV. The obtained results showed that all Trichoderma isolates considerably lowered the radial growth of P. ultimum, R. solani, and F. oxysporum in varying degrees. The scanning electron micrographs illustrate the mycoparasitic nature of Trichoderma sp. on F. oxysporum. The phytochemical analysis of C. procera indicated that phenolic contents were the major compounds found in extracts, such as vanillin (46.79%), chlorogenic acid (30.24%), gallic acid (8.06%), and daidzein (3.45%) but including only a low amount of the flavonoid compounds rutin, naringenin, and hesperetin. The Pot experiment's findings showed that cantaloupe was best protected against wilting and root rot diseases when it was treated with both Trichoderma sp. culture filtrates (10%) and C. procera extract of (15 mg/mL), both alone and in combination. This study demonstrates that the application of bio agent Trichoderma spp. filtrate with C. procera phenol extract appears useful for controlling wilting and root rot disease in cantaloupe. This innovative approach could be used as an alternative to chemical fungicide for the control of wilting and rot root diseases.
