Role of green-synthesized and characterization of calcium oxide nanoparticles for sustainable wheat growth in saline environments

Salinity is a major abiotic stress limiting wheat (Triticum aestivum L.) productivity. This study investigated the efficacy of green-synthesized calcium oxide nanoparticles (CaONPs) from Nigella sativa seeds in enhancing wheat growth under saline conditions. CaONPs were synthesised and characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and UV–Vis spectroscopy. The particles exhibited a mean diameter of 5.65 nm, spherical morphology, distinct crystalline peaks (27–68°), and functional groups (O–H, C=O, Ca–O) contributing to stability. Wheat seeds were treated with CaONPs at 0, 10, 50, 100, and 500 mg/L under saline stress. At 10 mg/L, shoot length, root length, and plant height increased by 4.38%, 10.63%, and 16.25%, respectively; leaf area expanded by 3.24%. At 500 mg/L, germination rate improved by 25%, fresh biomass increased by 26.3%, and dry biomass by 66.67%. Principal component analysis (PCA) confirmed significant dose-dependent improvements in growth parameters. SEM and XRD analyses post-treatment indicated nanoparticle stability and persistence in the growth medium. The results demonstrate that N. sativa-derived CaONPs effectively alleviate salinity-induced growth inhibition, with concentrations between 10–500 mg/L offering a sustainable nanobiotechnological strategy for enhancing wheat performance under saline conditions.