Infective stage of Puccinia on wheat is :-

Options

A. Basidiospores
B. Pycnia
C. Aeciospores
D. Teleutospores

Answer

To determine the infective stage of Puccinia on wheat, we need to analyze the given options one by one.

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for the infective stage of the fungus Puccinia, which is known to cause wheat rust.

2. **Analyzing Option 1 - Basidiospores**:
- Basidiospores are produced by Basidiomycetes fungi and are not specific to Puccinia.
- **Conclusion**: This option is incorrect.

3. **Analyzing Option 2 - Pycnia**:
- Pycnia refer to a structure that produces pycniospores, which are involved in the sexual reproduction of some fungi but are not the infective stage of Puccinia.
- **Conclusion**: This option is also incorrect.

4. **Analyzing Option 3 - Aeciospores**:
- Aeciospores are indeed the infective spores of Puccinia. They are produced in the aecium and can infect the host plant, leading to the development of the disease.
- **Conclusion**: This option is correct.

5. **Analyzing Option 4 - Teliospores**:
- Teliospores are thick-walled resting spores that are produced by some fungi, including Puccinia, but they are not the infective stage. They serve as a survival mechanism rather than a means of infection.
- **Conclusion**: This option is incorrect.

### Final Answer:
The infective stage of Puccinia on wheat is **Aeciospores** (Option 3).

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