Which one of the following is commonly used in transfer of foreign DNA into crop plants?

Options

A. Penicillium expansum
B. Trichoderma harzianum
C. Meloidogyne incognita
D. Agrobacterium tumefaciens

Answer

**Step-by-Step Solution:**

1. **Understanding the Question:**
The question asks about the common method used for transferring foreign DNA into crop plants.

2. **Analyzing the Options:**
- **Option A: Penicillium expansum**
- This is a blue mold that causes post-harvest decay in stored apples and produces carcinogenic mycotoxins. It is not used for DNA transfer.

- **Option B: Trichoderma harzianum**
- This is a biofungicide used to combat fungal pathogens. While it has agricultural applications, it is not primarily used for transferring DNA.

- **Option C: Meloidogyne incognita**
- Known as the southern root knot nematode, it affects plant roots but does not facilitate DNA transfer.

- **Option D: Agrobacterium tumefaciens**
- This bacterium is known for its ability to transfer DNA into plant cells. It contains a plasmid called Ti (tumor-inducing) plasmid, which carries T-DNA that can integrate into the plant genome, making it a key tool in genetic engineering.

3. **Identifying the Correct Answer:**
Based on the analysis, **Agrobacterium tumefaciens** is the correct answer as it is commonly used for the transfer of foreign DNA into crop plants.

4. **Conclusion:**
The commonly used organism for transferring foreign DNA into crop plants is **Agrobacterium tumefaciens**.

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