Which one of the following microbes forms symbiotic association with plants and helps them in their nutrition?

Explanation

The microbe that forms a symbiotic association with plants and aids in their nutrition is **Glomus**. Here's an explanation of all the options:1. **Azotobacter:** Azotobacter is a free-living nitrogen-fixing bacterium. It doesn't form symbiotic associations with plants but can contribute to nitrogen availability in the soil.2. **Aspergillus:** Aspergillus is a common filamentous fungus, but it is not typically known for forming symbiotic relationships with plants. Instead, it's often associated with various types of decomposition and growth in non-symbiotic environments.3. **Glomus:** Glomus is a type of mycorrhizal fungus. It forms a mutualistic symbiotic association with the roots of most plants. This association, known as arbuscular mycorrhiza, enhances the plant's ability to absorb water and essential nutrients, particularly phosphorus, from the soil. It's a crucial contributor to plant nutrition.4. **Trichoderma:** Trichoderma is a genus of fungi known for its ability to act as a biocontrol agent against plant pathogenic fungi. It can help protect plants from certain diseases but doesn't typically form direct symbiotic relationships with plants for nutritional benefits.So, the correct option is **Glomus** when it comes to forming a symbiotic association with plants and assisting in their nutrition.