Shoot bud formation is tissue culture is promoted by

Options

A. High auxin : Low Cytokinin
B. Low Auxin : High Cytokinin
C. Auxin : Sucrose
D. `GA_(3)` : Cytokinin

Answer

**Step-by-Step Solution:**

1. **Understanding Tissue Culture**: Tissue culture is a technique used to grow plants in a controlled environment using plant cells or tissues. It relies on the manipulation of plant hormones to promote growth and development.

2. **Key Plant Hormones**: The two primary hormones involved in shoot and root formation during tissue culture are auxins and cytokinins.
- **Auxins**: Typically promote root formation.
- **Cytokinins**: Promote shoot formation.

3. **Hormonal Concentration Effects**:
- When **auxin is in high concentration** and **cytokinin is in low concentration**, it leads to the formation of roots.
- When **auxin is in low concentration** and **cytokinin is in high concentration**, it promotes the formation of shoot buds.
- A balance of auxin and cytokinin can lead to the formation of callus, which is an undifferentiated mass of cells.

4. **Evaluating the Options**:
- **Option 1**: High auxin and low cytokinin → Promotes root formation (not correct for shoot bud formation).
- **Option 2**: Low auxin and high cytokinin → Promotes shoot bud formation (correct).
- **Option 3**: Auxin equal to sucrose → This does not directly relate to shoot bud formation.
- **Option 4**: GA3 equal to cytokinin → GA3 (Gibberellic acid) is not directly related to promoting shoot bud formation in this context.

5. **Conclusion**: The correct answer is **Option 2: Low auxin and high cytokinin** promotes shoot bud formation in tissue culture.

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