Question: Causal Agent of Whip Smut of Sugarcane:
Options:
Flag smut of wheat
Loose smut of wheat
Ustilago scitaminea
Covered smut of barley
Whip smut of sugarcane is caused by the fungus Ustilago scitaminea. The disease is characterized by the formation of a black, whip-like structure (composed of fungal spores) at the tip of the sugarcane shoots. This disease leads to reduced sugar yield and stunted growth of the crop.
📌Other Options Explanations:
-Flag smut of wheat is caused by Urocystis agropyri and results in blackened flag leaves.
-Loose smut of wheat is caused by Ustilago tritici and infects the wheat kernels, replacing them with dark, powdery spores.
-Covered smut of barley is caused by Ustilago hordei and manifests as black, enclosed smut balls within the barley kernels.
🔑Key Points:
-The disease is caused by the fungus Ustilago tritici which survives as dormant mycelium in the embryo of infected grain.
-The major symptom of loose smut is the "smutted" grain heads, which contain masses of black or brown spores.
-After spores disperse, only a bare rachis remains with a few fragments of glumes or awns.
-These spores, in turn, infect other wheat plants at flowering, causing seed infection.