________ acts as a biofertiliser in symbiotic association with legumes.

Options

A. Rhizobium
B. Trichoderma
C. Azotobacter
D. Mycobacterium

Answer

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks which microorganism acts as a biofertilizer in symbiotic association with legumes.

2. **Understand the Options**: The options provided are:
- Option 1: Rhizobium
- Option 2: Trichoderma
- Option 3: Azotobacter
- Option 4: Mycobacterium

3. **Analyze Each Option**:
- **Mycobacterium**: This is a type of bacteria that acts as a pathogen, causing diseases such as tuberculosis in humans. It does not function as a biofertilizer.
- **Azotobacter**: While it is a nitrogen-fixing bacterium, it does not form a symbiotic relationship with plants. Instead, it is free-living and contributes to soil fertility but is not a biofertilizer in the context of legumes.
- **Trichoderma**: This is a fungus that helps in plant growth but does not specifically act as a biofertilizer through a symbiotic relationship with legumes.
- **Rhizobium**: This is a bacterium that forms a symbiotic association with leguminous plants (like pulses). It lives in the root nodules of these plants and fixes atmospheric nitrogen, converting it into a form that the plants can use for nutrition.

4. **Conclusion**: Based on the analysis, the correct answer is **Rhizobium**, as it acts as a biofertilizer in symbiotic association with legumes.

**Final Answer**: Rhizobium acts as a biofertiliser in symbiotic association with legumes.

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