Question

Name the disease that is characterized by spores that accumulate in soot like masses (a deep black powdery or flaky substance) in seeds, leaves, stems, flower parts and bulbs.

• A. Smut
• B. Mildew
• C. Rust
• D. Spots

Hint:

Keyword for Smut = "Black soot-like powdery mass".
Keyword for Rust = "Rusty/Orange pustules".
Keyword for Mildew = "White powdery coating".

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The question asks to identify a fungal plant disease based on its characteristic symptom: the accumulation of black, soot-like powdery masses of spores.

Step 2: Detailed Explanation:

• Smut is a disease caused by fungi in the order Ustilaginales. The term "smut" itself refers to the dark, soot-like appearance of the fungal spores (teliospores).

• These spores typically replace the plant's reproductive organs, such as grain kernels, with a black powdery mass. However, they can also affect leaves, stems, and other parts.

• Common examples include Loose Smut of Wheat and Grain Smut of Sorghum.

• Mildew (B) is characterized by white or gray patches (powdery or downy). Rust (C) appears as orange, yellow, or reddish-brown pustules resembling oxidized iron. Spots (D) are localized lesions of dead tissue.

• The description "deep black powdery or flaky substance" is a diagnostic feature specific to Smut diseases.

Step 3: Final Answer: The disease described is Smut.