Disease resistance is obtained through

Options

A. colchicine treatment
B. crossing with wild relatives
C. x ray treatment
D. hormone treatment

Answer

### Step-by-Step Solution:

1. **Understanding Disease Resistance**:
- Disease resistance in plants refers to the ability of a plant to prevent or withstand diseases caused by pathogens. This is crucial for maintaining crop yields and preventing losses.

2. **Role of Genetics**:
- The genetics of a plant plays a significant role in its resistance to diseases. Certain genes confer resistance, and these can be manipulated through breeding techniques.

3. **Classical Plant Breeding**:
- Classical plant breeding involves the deliberate crossing of closely or distantly related plants to create new varieties. The goal is to combine desirable traits, such as high yield and disease resistance.

4. **High Yielding Varieties (HYVs)**:
- High Yielding Varieties are those that have been bred for increased productivity. However, they may lack disease resistance, which is why it is important to introduce disease-resistant genes into these varieties.

5. **Crossing with Wild Relatives**:
- Wild relatives of cultivated plants often possess natural disease resistance. By crossing high yielding varieties with these wild relatives, breeders can introduce disease-resistant traits into the new hybrids.

6. **Conclusion**:
- Therefore, disease resistance is primarily obtained through the genetic manipulation of plants, specifically by crossing high yielding varieties with their wild relatives to incorporate disease-resistant genes.

### Final Answer:
Disease resistance is obtained through crossing high yielding varieties with wild relatives that possess disease-resistant traits.

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