Isolation and in vitro Antagonistic Potential of Endophytic Microorganisms against Whip Smut (Sporisorium scitamineum) on Sugarcane

Abstract

Sugarcane whip smut, caused by Sporisorium scitamineum, is among the most destructive fungal diseases affecting sugarcane production worldwide. This investigation aimed to isolate endophytic microorganisms from different sugarcane tissues and evaluate their antagonistic activity against S. scitamineum under in vitro conditions. Endophytic fungi and bacteria were isolated from the roots, canes and leaves of healthy sugarcane plants using standard microbiological techniques. Based on cultural and morphological characteristics, the fungal endophytes were identified as Trichoderma viride and Trichoderma longibrachiatum, whereas the bacterial endophytes were identified as Bacillus subtilis and Pseudomonas sp. Their antagonistic activity against S. scitamineum was assessed using the dual-culture technique. Significant variation in pathogen inhibition was observed among the tested endophytes. Trichoderma viride recorded the greatest inhibition of mycelial growth (84.24%), followed by Bacillus subtilis (80.84%), Trichoderma longibrachiatum (77.91%) and Pseudomonas sp. (67.40%). The comparatively high inhibition achieved by T. viride and B. subtilis indicates their antagonistic potential against the whip smut pathogen. These findings show that the tested endophytic microorganisms can suppress S. scitamineum under in vitro conditions. However, greenhouse and field studies are required to validate their efficacy before they can be recommended for the biological management of sugarcane whip smut. The study provides a comparative basis for prioritising isolates.