Assessment of Biochemicals and Growth Parameters in Pyricularia oryzae Inoculated Rice Seed Genotypes by Applying Chitin Nanofiber, Mycorrhiza, Trichoderma, and Botanicals

Rice blast disease, caused by Pyricularia oryzae, is a significant threat to global rice production, resulting in substantial yield losses. However, productivity losses due to rice blast disease are significant, and detailed knowledge of the management to control the disease and the enzymatic response linked to physiological resistance remains limited. A lab experiment was conducted to explore the effects of biological and botanical treatments on rice seedling health and pathogen resistance under rice blast (Pyricularia oryzae) inoculation from January to March 2025 at the Plant Protection Laboratory of Khulna University. Four rice genotypes (BRRI dhan28, BRRI dhan29, BRRI dhan74, and IR 64) were subjected to six treatments: Control (water), Neem extract, Tulshi extract, Trichoderma, Chitin Nanofiber (CNF), and Mycorrhiza. A factorial completely randomized design was used with three replications. Morphological parameters, including germination energy (GE), germination capacity (GC), germination percentage (GP), germination speed (GS), shoot and root length, fresh and dry weight, seedling vigor index (SVI), and biochemical properties such as concentrations of H₂O₂, protein, sugar, phenol, flavonoids, and antioxidants were measured. Results demonstrated that Mycorrhiza significantly improved GE (61.33%), GC (89.33%), GP (94.67%), GS (77.33%), shoot length (5.60 cm), and root length (7.67 cm), fresh weight of root and shoot (0.187 g) and SVI (1255.9), with the highest values observed in IR 64 and BRRI dhan74. Tulshi also showed notable improvements in seedling growth and biochemical responses, especially in BRRI dhan74, by increasing flavonoid and phenol concentrations. Trichoderma and CNF showed moderate positive effects on GP, GS, and biochemical parameters, while Neem demonstrated moderate improvements in protein and antioxidant levels. Mycorrhiza consistently led to the highest H₂O₂ reduction (84.33 µmol kg⁻¹ FW), demonstrating its superior ability to mitigate oxidative stress. These findings indicate that Mycorrhiza and Tulshi with IR 64 are highly effective in enhancing seedling vigor and mitigating oxidative stress, making them promising candidates for improving rice seedling resilience in pathogen-prone environments and making it a promising resistant benchmark for breeding programs. IR 64 demonstrates superior resilience to Pyricularia oryzae stress.

• Supervision