MORPHO-STRUCTURAL AND FUNCTIONAL ASSESSMENT OF DUAL-SYNTHESIZED ZNO AND SIO₂ NANOPARTICLES FOR ENHANCED SEED GERMINATION AND ANTIFUNGAL EFFICACY

Abstract

The production of high-quality and climate-resilient seeds is critical for ensuring food security under changing environmental conditions. Nanotechnology offers a promising, sustainable alternative to conventional agrochemical-based approaches for improving seed germination, vigor, and health. The present study aimed to synthesize zinc oxide (ZnO) nanoparticles using a sol–gel method and bio-synthesize silica (SiO₂) nanoparticles from sugarcane bagasse through a green approach, to characterize their physicochemical properties, and to evaluate their effects on germination, seedling vigor, and seed health of soybean (Glycine max L.).

ZnO nanoparticles were synthesized using zinc nitrate and potassium hydroxide, followed by calcination, while SiO₂ nanoparticles were obtained from sugarcane bagasse through acid extraction and thermal processing. The nanoparticles were characterized using SEM, TEM, SEM–EDX, and UV–Visible spectroscopy, confirming nano-scale size, characteristic morphology, and elemental purity. Uniformly dispersed nanoparticle suspensions were prepared at different concentrations (30–1200 ppm) and applied as seed treatments.

Results revealed a clear dose-dependent response in soybean seed performance. Lower concentrations, particularly 50 ppm, significantly enhanced germination percentage, shoot and root length, dry seedling weight, and vigor indices (VI-I and VI-II), while simultaneously reducing diseased seed incidence compared to the control. In contrast, higher concentrations (≥800 ppm) resulted in reduced growth and vigor, along with increased disease incidence, indicating phytotoxic effects at elevated doses. Multivariate analyses, including principal component analysis (PCA) and correlation heat maps, demonstrated strong positive associations among germination, growth, and vigor traits, and a strong negative association with diseased seeds.

The study highlights the dual functionality of ZnO and bio-derived SiO₂ nanoparticles in promoting seedling growth and improving seed health when applied at optimized concentrations. The use of sugarcane bagasse as a silica source further underscores the sustainability and circular economy potential of the approach. Overall, nanoparticle-based seed treatment at low concentrations represents a viable strategy for enhancing soybean seed quality and early crop establishment while reducing reliance on conventional agrochemicals.