The shoot branching depends upon the development of axillary buds but many of the buds in axillary position never grow out due to the

Options

A. Inhibitory factor present in the axillary bud
B. Inhibitory factor present in the apical bud
C. Inhibition under genetic control
D. None of the above

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks why many axillary buds do not grow out, despite their potential for shoot branching.

2. **Identifying Key Concepts**: The key concepts involved are axillary buds, shoot branching, and the role of plant hormones, particularly auxin.

3. **Role of Auxin**: Auxin, specifically Indole-3-acetic acid (IAA), is a plant hormone that promotes growth, particularly in the apical regions of the plant. It is responsible for the elongation of the plant and is concentrated at the tips of stems and leaves.

4. **Apical Dominance**: Auxin exhibits a phenomenon known as apical dominance, where the growth of the main shoot (apical bud) inhibits the growth of axillary buds. This means that as long as the apical bud is active and producing auxin, the axillary buds remain dormant.

5. **Inhibition of Axillary Buds**: The presence of auxin in the apical bud inhibits the development of the axillary buds. This is a crucial point because it explains why many axillary buds do not grow out; they are suppressed by the auxin produced at the apical bud.

6. **Conclusion**: The correct answer to the question is that many axillary buds do not grow out due to the inhibitory effect of auxin present in the apical bud.

7. **Final Answer**: The shoot branching depends upon the development of axillary buds, but many of the buds in axillary position never grow out due to the inhibitory factor present in the apical bud.

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