In grafting stock and scion ought to be joined

Options

A. Phloem to phloem
B. xylem to xylem
C. pith to pith
D. cambium to cambium

Answer

### Step-by-Step Solution:

1. **Understanding Grafting**: Grafting is a horticultural technique where two different plants are joined together to grow as a single composite plant. This involves connecting the root system of one plant (the stock) with the shoot system of another plant (the scion).

2. **Identifying the Parts**: In grafting:
- The **stock** refers to the part of the plant that provides the root system.
- The **scion** is the part that provides the shoot system.

3. **Joining Mechanism**: For successful grafting, the stock and scion must be joined in a specific manner. This involves aligning the vascular tissues of both plants.

4. **Vascular Tissue Connection**: The correct joining of the stock and scion is crucial for the graft to take. The following connections are essential:
- **Cambium to Cambium**: The cambium layer of the stock must touch the cambium layer of the scion for successful grafting.
- Other connections such as phloem to phloem, xylem to xylem, and pith to pith are not necessary for the graft to succeed.

5. **Importance of Cambium**: The cambium is a layer of actively dividing cells that is responsible for secondary growth in plants. This connection allows for the formation of callus tissue, which helps in healing and uniting the graft.

6. **Conclusion**: Therefore, the correct answer to the question is that the stock and scion ought to be joined **cambium to cambium**.