The pre-requistie for effective exploitation of natural genes available in the populations is:

Options

A. Collection and preservation of germplasm
B. Cross hybridization of selected parents
C. Testing the superior cultivars in farmers field
D. Commericialisation of crop varieties

Answer

**Step-by-Step Solution:**

1. **Understanding Germplasm**: Germplasm refers to the hereditary material that is passed down to offspring through germ cells. It encompasses the genetic resources necessary for breeding programs.

2. **Importance of Germplasm**: Germplasm serves as the raw material for plant breeders to develop new crop varieties. Without a diverse and preserved collection of germplasm, breeding efforts would lack the necessary genetic diversity.

3. **Evaluating the Options**:
- **Collection and Preservation of Germplasm**: This is essential as it ensures that the genetic material is available for future breeding and research.
- **Cross Hybridization of Selected Parents**: While important for creating genetic variation, it relies on having a diverse germplasm to begin with.
- **Testing Superior Cultivars in Farmer's Field**: This step is crucial for practical application but comes after germplasm collection.
- **Commercialization of Crop Varieties**: This involves bringing new varieties to market but is dependent on the prior steps of germplasm collection and breeding.

4. **Conclusion**: The prerequisite for effectively exploiting natural genes in populations is the collection and preservation of germplasm. This step is foundational for all subsequent breeding activities.

**Final Answer**: The prerequisite for effective exploitation of natural genes available in the populations is **collection and preservation of germplasm**.

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