In plants, which of the following disease is caused by bacteria?

Options

A. Mosaic disease of tobacco
B. Citrus canker
C. Late blight's of potato
D. Potato spindle tuber disease

Answer

To determine which of the diseases listed is caused by bacteria, we will analyze each option one by one.

### Step-by-Step Solution:

1. **Identify the Diseases**:
- We have four diseases to consider:
- Mosaic disease of tobacco
- Citrus canker
- Late blight of potato
- Potato spindle tuber disease

2. **Analyze Each Disease**:
- **Mosaic disease of tobacco**:
- This disease is caused by the Tobacco Mosaic Virus (TMV). Since it is caused by a virus, it is not caused by bacteria.

- **Citrus canker**:
- This disease is characterized by lesions on various citrus species and is caused by *Xanthomonas citri*, which is a bacterium. Therefore, this disease is indeed caused by bacteria.

- **Late blight of potato**:
- This disease is caused by *Phytophthora infestans*, which is a water mold (oomycete) and not a bacterium. Thus, it is not caused by bacteria.

- **Potato spindle tuber disease**:
- This disease is caused by a viroid, which is a type of infectious agent similar to viruses but lacks a protein coat. Since viroids are not bacteria, this disease is also not caused by bacteria.

3. **Conclusion**:
- After analyzing all the options, the only disease caused by bacteria is **Citrus canker**.

### Final Answer:
The disease caused by bacteria in plants is **Citrus canker**.

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