An example of a disease caused by the prokaryotic pathogen is

Options

A. red rot of sugarcane.
B. late blight of potato .
C. black rot of crucifers .
D. brown rust of wheat .

Answer

To solve the question, "An example of a disease caused by the prokaryotic pathogen is," we need to analyze the options provided and identify which one corresponds to a disease caused by a prokaryotic organism (bacteria).

### Step-by-Step Solution:

1. **Understand the Pathogen Types**:
- Prokaryotic pathogens are primarily bacteria, while eukaryotic pathogens include fungi, protozoa, and some parasites.

2. **Evaluate the First Option: Red Rot of Sugar**:
- This disease is caused by the fungus *Colletotrichum falcatum*. Since fungi are eukaryotic, this option is incorrect.

3. **Evaluate the Second Option: Late Blight of Potato**:
- This disease is caused by the fungus *Phytophthora infestans*. Again, since this is a fungus (eukaryotic), this option is also incorrect.

4. **Evaluate the Third Option: Black Rot of Crucifers**:
- This disease is caused by the bacterium *Xanthomonas campestris*. Since this is a prokaryotic pathogen (bacteria), this option is correct.

5. **Evaluate the Fourth Option: Brown Rust of Wheat**:
- This disease is caused by the fungus *Puccinia triticina*. As this is also a eukaryotic organism, this option is incorrect.

6. **Conclusion**:
- The only option that represents a disease caused by a prokaryotic pathogen is the third option: Black Rot of Crucifers.

### Final Answer:
The correct answer is **Black Rot of Crucifers**.

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