Antifungal Activity and Biochemical Characteristics of Natural α-Pinene Against Rhizoctonia solani

Rice sheath blight, caused by Rhizoctonia solani, has spread worldwide and causes serious economic losses. It is critically important to investigate alternative fungicides in light of the emergence of fungicide resistance and chemical residues. This study evaluated the natural substance α-pinene's activity. The R. solani strain's EC₅₀ values for Taxodium 'Zhongshanshan' essential oil suppression of mycelial growth ranged from 201.99 to 1,523.37 μg/ml, and the EC₅₀ value of α-pinene against R. solani was 111.31 μg/ml. Cell membrane permeability rose considerably after α-pinene treatment, although mycelia deformed with more branches, no sclerotia formed, and the chitin content reduced. At 1,000 μg/ml, α-pinene demonstrated over 90% effectiveness against R. solani in pot trials. All things considered, α-pinene exhibits promise as a natural substitute for synthetic fungicides or as a building block for the creation of novel fungicides to combat rice sheath blight. The biological properties aid in the comprehension of α-pinene's mechanism of action against R. solani.