Pathogenicity, Phytotoxicity and Enzymatic Potential of Sorghum Grain Mold Pathogens

Sorghum grain mold disease is a serious threat for sorghum cultivation. Being a complex disease involving many fungi, basic understanding of pathogenicity is essential. In the present investigation, 14 sorghum seed samples were tested by dry seed examination and blotter method for the presence of fungi. The results revealed prominent infection of Alternaria spp. (21%) and Fusarium spp. (23%). In seedling pathogenicity test Drechslera sp. reduced vigour index significantly by reducing shoot and root lengths. Phytotoxicity of selected fungi in detached leaf bioassay revealed toxicity to monocot leaves. The Curvularia sp., Drechslera sp., and Fusarium sp. induced necrosis in rice, sorghum and sugarcane leaves. Enzymatic potential of selected fungi was realised in plate assay. The Drechslera sp. and Fusarium sp. are prominent producers of enzymes essential for pathogenicity. The present work demonstrated wide occurrence of grain mold pathogens in sorghum seed samples and also assessed their pathogenicity. The detached leaf bioassay and enzyme plate assays were useful in the detection of virulence in fungal isolates.