Chitosan Enhances Germination and Growth of Rice Plant (Oryza sativa) while controlling Rhizoctonia solani Infection

Rice is one of the world’s major staple crops, and improving its germination and growth is paramount for food safety. In the present study, IR64 rice seeds were treated with commercial and biologically synthesized chitosan using Streptomyces griseoincarnatus to assess their impact on germination efficiency, growth performance, and disease resistance. Synthesized chitosan significantly reduced the mean germination time and T₅₀, but improved the germination index, suggesting quicker and more synchronous germination. Synthesized chitosan also encouraged more root and shoot growth, a higher number of tillers, wider leaves, biomass production, chlorophyll content, and ultimately better grain yield. Synthesized chitosan was highly active against Rhizoctonia solani , lowering the severity of disease and activating plant defense by elevating PR 10 gene expression by ~70-fold. The findings indicate that biologically synthesized chitosan acts both as a biostimulant and biocontrol agent and providing a biodegradable and renewable alternative to traditional agrochemicals for enhancing rice growth, productivity, and stress tolerance.