Which one is the wrong pairing for the disease and its causal organism?

Options

A. Loose smut of wheat - Ustilago nuda
B. Root - knot of vegetables - Meloidogy- ne sp.
C. Late blight of potato - Alternaria solani
D. Black rust of wheat - Puccinia graminis

Answer

To determine the wrong pairing for the disease and its causal organism, we will analyze each option provided in the question.

### Step 1: Identify the diseases and their causal organisms in the options.
- **Option A**: Loose smut of wheat - Causal organism: Ustilago tritici
- **Option B**: Root knot of vegetables - Causal organism: Meloidogyne species
- **Option C**: Late blight of potato - Causal organism: Alternaria solani
- **Option D**: Black rust of wheat - Causal organism: Puccinia graminis

### Step 2: Verify the correctness of each pairing.
- **Option A**: Loose smut of wheat is indeed caused by Ustilago tritici. This is a correct pairing.
- **Option B**: Root knot of vegetables is caused by Meloidogyne species. This is also a correct pairing.
- **Option C**: Late blight of potato is incorrectly paired with Alternaria solani. The correct causal organism for late blight of potato is Phytophthora infestans. Therefore, this is the wrong pairing.
- **Option D**: Black rust of wheat is caused by Puccinia graminis. This is a correct pairing.

### Step 3: Conclude which option is the wrong pairing.
Based on the analysis, the wrong pairing is **Option C**: Late blight of potato - Alternaria solani.

### Final Answer:
The wrong pairing for the disease and its causal organism is **Option C: Late blight of potato - Alternaria solani**.

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