Breeding for disease resistance requires

Options

A. A good source of resistance
B. Planned hybridisation
C. Disease test
D. All the above.

Answer

**Step-by-Step Solution:**

1. **Understanding the Concept of Disease Resistance in Plants:**
- Breeding for disease resistance involves developing plant varieties that can withstand infections from pathogens like bacteria, fungi, and viruses. This is crucial for sustainable agriculture as it reduces the need for chemical treatments.

2. **Identifying the Requirements for Breeding:**
- To successfully breed plants for disease resistance, several key components are necessary:
- A good source of resistance: This involves identifying and screening germplasm (genetic material) for plants that exhibit resistance to specific diseases.
- Plant hybridization: Once a resistant source is identified, hybridization (cross-breeding) of the selected resistant plants with other plants is performed to combine desirable traits.
- Disease testing: After hybridization, the new hybrids must be tested for their resistance to diseases before they can be released as new varieties.

3. **Evaluating the Options:**
- The question provides four options:
a) A good source of resistance
b) Plant hybridization
c) Disease test
d) All of the above
- Each of the first three options is a critical step in the breeding process. Therefore, the correct answer must encompass all these steps.

4. **Conclusion:**
- Since all the components (a good source of resistance, plant hybridization, and disease testing) are essential for breeding plants for disease resistance, the final answer is that breeding for disease resistance requires **all of the above**.

**Final Answer:** All of the above.

---