Question

Rot diseases are caused by

• A. Fusarium oxysporum
• B. Fusarium solani
• C. Ralstonia solanacearum
• D. Ralstonia pseudosolanacearum

Hint:

Wilt = Clogged pipes (Xylem).
Rot = Dissolved walls (Tissue degradation).
Fusarium solani is often a soil-borne complex involved in root rot.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question asks to differentiate between pathogens based on the specific type of symptom they produce: Wilt vs Rot.

Step 2: Detailed Explanation:

• Fusarium solani (B): This species is well-known for causing rotting symptoms, such as root rot, dry rot of potato tubers, and stem rot in various crops. Unlike wilt pathogens, it actively degrades the host tissue using cell-wall-degrading enzymes.

• Fusarium oxysporum (A): This species is the classic cause of vascular wilts (e.g., Fusarium wilt of tomato or banana). It invades the xylem vessels and blocks water transport, leading to wilting without necessarily rotting the outer tissues initially.

• Ralstonia solanacearum (C) and R. pseudosolanacearum (D): These are bacterial wilt pathogens. They reside in the xylem and produce extracellular polysaccharides (EPS) that clog the vessels, leading to rapid wilting.
Final Answer:
While F. oxysporum and Ralstonia are primarily associated with wilting, F. solani is specifically characterized as a rot-causing pathogen.