Occurrence of dikaryotic mycelium mainly is the characteristic of :-

Options

A. Myxomycetes
B. Phycomycetes
C. Deuteromycetes
D. Basidiomycetes

Answer

To solve the question regarding the occurrence of dikaryotic mycelium, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Dikaryotic Mycelium**:
- Dikaryotic mycelium is a type of fungal mycelium that contains two genetically distinct nuclei in each cell. This condition arises after the fusion of two fungal hyphae, where the nuclei do not immediately fuse, leading to a stage where two nuclei coexist in a single cell.

2. **Identifying Fungal Groups**:
- The question provides four options related to different groups of fungi: Mycomycetes, Phycomycetes, Deuteromycetes, and Decidomycetes. We need to identify which of these groups is characterized by the presence of dikaryotic mycelium.

3. **Analyzing the Options**:
- **Mycomycetes**: This term is not commonly used in modern taxonomy and does not specifically refer to a group known for dikaryotic mycelium.
- **Phycomycetes**: This group includes fungi that typically do not exhibit dikaryotic mycelium. They reproduce asexually and have a simpler structure.
- **Deuteromycetes**: Also known as imperfect fungi, this group primarily reproduces asexually and does not have a dikaryotic stage.
- **Basidiomycetes**: This group includes fungi such as mushrooms and is known for the presence of dikaryotic mycelium. After the fusion of hyphae from different mating types, the resulting mycelium can remain dikaryotic for a significant part of its life cycle.

4. **Conclusion**:
- Based on the analysis, the occurrence of dikaryotic mycelium is a characteristic feature of **Basidiomycetes**. Therefore, the correct answer is **Option D: Basidiomycetes**.

### Final Answer:
The occurrence of dikaryotic mycelium mainly is the characteristic of **Basidiomycetes** (Option D).

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