`N_2` fixing bacteria in non-legume plants are:

Options

A. Frankia
B. Rhizobia
C. Plasmodium
D. Aspergillus

Answer

To answer the question about nitrogen-fixing bacteria in non-legume plants, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Nitrogen Fixation**:
- Nitrogen fixation is the process by which atmospheric nitrogen (N₂) is converted into ammonia (NH₃), which plants can use for growth.

2. **Identifying Nitrogen-Fixing Bacteria**:
- There are two main types of nitrogen-fixing bacteria:
- **Symbiotic Nitrogen-Fixing Bacteria**: These bacteria form a symbiotic relationship with plants to fix nitrogen.
- **Free-Living Nitrogen-Fixing Bacteria**: These bacteria can fix nitrogen independently without forming a relationship with plants.

3. **Evaluating the Options**:
- The options given are Franckiae, Rhizobia, Plasmodium, and Aspergillus.
- **Franckiae**: This is a symbiotic nitrogen-fixing bacterium that associates with non-legume plants, such as certain actinorhizal plants.
- **Rhizobia**: These are symbiotic nitrogen-fixing bacteria that specifically associate with leguminous plants, not non-legumes.
- **Plasmodium**: This is a protozoan that causes malaria and is not involved in nitrogen fixation.
- **Aspergillus**: This is a genus of fungi and does not fix nitrogen.

4. **Conclusion**:
- Based on the evaluation, the correct answer to the question is **Franckiae**, as it is the nitrogen-fixing bacterium that associates with non-legume plants.

### Final Answer:
The nitrogen-fixing bacteria in non-legume plants are **Franckiae**.

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