The genetic mechanism which prevents selfpollen from fertilising the ovules by inhibiting pollen germination on the pistil of same flower is called

Options

A. Herkogamy
B. Heterostyly
C. Self-Sterility
D. Dichogamy

Answer

To answer the question regarding the genetic mechanism that prevents self-pollen from fertilizing the ovules by inhibiting pollen germination on the pistil of the same flower, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Concept**: The question is about a genetic mechanism that prevents self-fertilization in flowering plants. Self-fertilization occurs when pollen from the same flower fertilizes its own ovules.

2. **Identifying Mechanisms**: There are several mechanisms that flowering plants use to avoid self-fertilization. Two key terms related to this are:
- **Self-sterility**: This is a genetic mechanism where either the pollen is sterile, or the stigma is non-receptive to its own pollen. This prevents self-pollination.
- **Dicogamy**: This mechanism involves the timing of the maturation of anthers and stigmas, ensuring they do not mature at the same time, thus preventing self-pollination.

3. **Focusing on the Question**: The question specifically asks for the mechanism that inhibits pollen germination on the pistil of the same flower. This aligns with the concept of self-sterility, where the plant's genetic makeup ensures that self-pollen cannot fertilize the ovules.

4. **Conclusion**: Therefore, the correct answer to the question is **self-sterility**. This genetic mechanism effectively prevents self-pollen from fertilizing the ovules by inhibiting the germination of the pollen on the stigma of the same flower.

### Final Answer:
The genetic mechanism which prevents self-pollen from fertilizing the ovules by inhibiting pollen germination on the pistil of the same flower is called **self-sterility**.