Pollen grains lose viability within 30 minutes of their release in:

Options

A. Rice and wheat
B. Rosaceae and grasses
C. Leguminous plants
D. Members of Poaceae and Solanaceae

Answer

### Step-by-Step Solution:

1. **Understanding Pollen Viability**:
- Pollen viability refers to the ability of pollen grains to survive, germinate, and develop after being released from the anther.

2. **Analyzing the Options**:
- The question provides several options:
- Rice and Wheat
- Rosaceae and Grasses
- Leguminous Plants
- Members of Poaceae and Solanaceae

3. **Evaluating Each Option**:
- **Rice and Wheat**: Research indicates that the pollen grains of these plants lose viability within approximately 30 minutes after their release.
- **Rosaceae**: Pollen grains from this family typically have a viability of about 1 month.
- **Grasses**: Pollen grains from grasses have a viability of around 150 minutes.
- **Leguminous Plants**: Similar to Rosaceae, these plants also have a pollen viability of about 1 month.
- **Members of Poaceae and Solanaceae**: The pollen viability for these groups is also around 1 month.

4. **Conclusion**:
- Based on the analysis, the correct answer is **Rice and Wheat**, as their pollen grains lose viability within 30 minutes of release.

### Final Answer:
Pollen grains lose viability within 30 minutes of their release in **Rice and Wheat**.

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