Find out the plant growth regulator which is used to initiate flowering and for synchronised fruit set in pineapples

Options

A. Auxins
B. Gibberellins
C. Ethylene
D. Cytokinin

Answer

To find the plant growth regulator that initiates flowering and synchronizes fruit set in pineapples, we can analyze the different plant hormones mentioned in the question.

### Step-by-Step Solution:

1. **Identify the Plant Growth Regulators**: The question provides four options: Auxin, Gibberellins, Ethylene, and Cytokinins. We need to evaluate each one to determine which is responsible for flowering and fruit set in pineapples.

2. **Evaluate Auxin**: Auxin is primarily involved in processes like apical dominance and parthenocarpy (development of fruits without fertilization). It does not play a significant role in initiating flowering or synchronizing fruit set in pineapples.

3. **Evaluate Gibberellins**: Gibberellins are known to promote stem elongation, seed germination, and other growth processes. However, they are not specifically known for initiating flowering or synchronizing fruit set in pineapples.

4. **Evaluate Ethylene**: Ethylene is a plant hormone that is crucial for fruit ripening, promoting senescence, and abscission. Importantly, ethylene is also known to initiate flowering and synchronize fruit set in pineapples. This makes it a strong candidate for the question.

5. **Evaluate Cytokinins**: Cytokinins primarily promote cell division and can delay senescence. They do not specifically initiate flowering or synchronize fruit set in pineapples.

6. **Conclusion**: Based on the evaluation, the plant growth regulator responsible for initiating flowering and synchronizing fruit set in pineapples is **Ethylene**.

### Final Answer:
The plant growth regulator used to initiate flowering and for synchronized fruit set in pineapples is **Ethylene**.

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