Question

Match the following rice diseases in Group I with their causal agents in Group II.

• A. P-5; Q-3; R-2; S-1
• B. P-4; Q-2; R-5; S-3
• C. P-4; Q-5; R-3; S-1
• D. P-5; Q-4; R-1; S-2

Hint:

Always remember the classical rice disease associations: Blast (Magnaporthe grisea), False smut (Ustilaginoidea virens), Sheath blight (Rhizoctonia solani), and Downy mildew (Sclerophthora macrospora). These are frequently asked in plant pathology questions.

Answer 1

The Correct Option is A

Step 1: Rice blast disease (P)
The most serious rice disease worldwide is Blast, caused by the fungus Magnaporthe grisea (also called Pyricularia oryzae). This matches with option (5). Step 2: False smut of rice (Q)
False smut is caused by the fungus Ustilaginoidea virens, which converts grains into large greenish or yellow spore balls. This matches with option (3). Step 3: Sheath blight of rice (R)
Sheath blight is caused by the soil-borne fungus Rhizoctonia solani, which infects the leaf sheath near water level. This matches with option (2). Step 4: Downy mildew of rice (S)
Downy mildew is caused by Sclerophthora macrospora, an oomycete pathogen. This matches with option (1). Therefore, the correct matching is: P-5; Q-3; R-2; S-1.