Synthesis of Titanium Dioxide-Embedded Alginate–Chitosan-Based Coating for Enhanced Wheat Seed Germination under Abiotic Stress

Abstract

This research aimed to develop and evaluate titanium dioxide-embedded sodium alginate/chitosan-based active coatings for wheat seeds to enhance seed germination and early seedling growth. For this purpose, Alg-Cs-TiO₂ nanocomposite coatings were synthesized and applied to wheat seeds to improve germination, seedling growth, and resistance against abiotic stress. Chitosan (Cs) beads were initially reinforced with TiO₂ nanoparticles, and the beads were further coated with sodium alginate (Alg) to form Alg-Cs-TiO₂ beads. Characterization techniques, including scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), and thermogravimetric analysis (TGA), confirmed the successful incorporation of TiO₂ into the Alg-Cs matrix, improving crystallinity, thermal stability, and structural integrity. Antibacterial activity assays demonstrated enhanced inhibition of Escherichia coli and Staphylococcus aureus, with Alg-Cs-TiO₂ beads exhibiting the highest antibacterial effectiveness. Seed germination trials showed that Alg-Cs-TiO₂ coatings significantly improved seedling length by 0.524 cm, coleoptile length by 3.19 cm, shoot length by 28.887 cm, root length by 17.8 cm, and root weight by 0.129 g compared to uncoated seeds. The TiO₂ nanoparticles facilitated UV absorption, stress tolerance, and pathogen resistance, contributing to enhanced plant growth. This study highlighted Alg-Cs-TiO₂ coatings as a sustainable and effective biopolymer-based approach for the improvement of wheat seed performance in challenging environmental conditions.