In plants, embryos arising from interspecific crosses abort, due to

Options

A. Hybrid inviability
B. Hybrid sterility
C. Hybrid breakdown
D. Gametic isolation.

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks why embryos from interspecific crosses in plants abort. This involves understanding the reproductive barriers that exist between different species.

2. **Identifying Reproductive Barriers**: There are two main types of reproductive barriers:
- **Prezygotic barriers**: These prevent fertilization from occurring.
- **Postzygotic barriers**: These occur after fertilization has taken place.

3. **Focusing on Postzygotic Barriers**: Since the question specifically mentions embryos, we need to focus on postzygotic barriers, which affect the viability of the zygote or embryo after fertilization.

4. **Exploring the Options**:
- **Hybrid Inviability**: This occurs when the hybrid zygote fails to develop properly and does not reach maturity. This is a common outcome in interspecific crosses.
- **Hybrid Sterility**: This refers to hybrids that are born but are unable to reproduce (e.g., mules).
- **Hybrid Breakdown**: This occurs in subsequent generations where the hybrids may be fertile but their offspring are weak or sterile.
- **Gametic Isolation**: This prevents fertilization from occurring in the first place, meaning no zygote is formed.

5. **Conclusion**: Since the question specifically mentions embryos aborting, the most relevant option is **hybrid inviability**. This means that the embryos formed from the interspecific crosses do not develop into healthy plants and thus abort.

### Final Answer:
Embryos arising from interspecific crosses abort due to **hybrid inviability**.

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