The seeds of which plant cannot germinate and establish without the presence of mycorrhizae

Options

A. Cycas
B. Selaginella
C. Pinus
D. All of these

Answer

To determine which plant's seeds cannot germinate and establish without the presence of mycorrhizae, we will analyze each option provided.

### Step-by-Step Solution:

1. **Understanding Mycorrhizae**: Mycorrhizae are symbiotic associations between fungi and plant roots. They play a crucial role in nutrient uptake, especially phosphorus, and can enhance seed germination and plant establishment.

2. **Evaluating the Options**:
- **Option 1: Cycas**: The seeds of Cycas can germinate without the presence of mycorrhizae. Therefore, this option is incorrect.
- **Option 2: Selaginella**: Similarly, Selaginella seeds can also germinate without mycorrhizal associations. This option is also incorrect.
- **Option 3: Pinus**: Pinus species typically have a mutualistic relationship with mycorrhizal fungi, but they can germinate without them. Thus, this option is incorrect as well.
- **Option 4: All of these**: This option suggests that all the previous plants cannot germinate without mycorrhizae, which is not true based on our analysis.

3. **Conclusion**: After evaluating all the options, none of the plants listed (Cycas, Selaginella, and Pinus) require mycorrhizae for germination. Therefore, the correct answer is that none of the options provided are plants whose seeds cannot germinate without mycorrhizae.

### Final Answer:
None of the options listed (Cycas, Selaginella, Pinus) require mycorrhizae for seed germination.

---