All given statements are correct w.r.t. photoperiodism, except

Options

A. Discovered by garner and allard in a variety of tobacco
B. Stimulus is received by young leaves
C. Florigen is hypothetical hormone produced in response to stimulus
D. Florigen is transported to bud through phloem

Answer

To solve the question regarding photoperiodism and identify the incorrect statement, we can follow these steps:

### Step 1: Understand Photoperiodism
Photoperiodism is the physiological reaction of organisms to the length of day or night. It is particularly important in flowering plants, where the duration of light and darkness influences flowering.

**Hint:** Remember that photoperiodism relates to how plants respond to light and dark cycles.

### Step 2: Analyze Each Statement
We need to evaluate each statement provided to determine which one is incorrect.

1. **Statement 1**: Photoperiodism was first discovered by Gardner and Allard in 1920 using the Maryland Mammoth tobacco variety.
- This statement is correct as it accurately reflects historical facts about the discovery of photoperiodism.

**Hint:** Look for historical context in statements about scientific discoveries.

2. **Statement 2**: The stimulus for photoperiodism is received by the young leaves.
- This statement is misleading. While young leaves can be involved, it is the mature leaves that primarily receive the photoperiodic stimulus.

**Hint:** Consider which parts of the plant are most involved in receiving light signals.

3. **Statement 3**: Florigen is a hypothetical hormone produced in response to the photoperiodic stimulus.
- This statement is correct. Florigen is indeed considered a hormone that promotes flowering in response to light conditions.

**Hint:** Hormonal responses in plants often relate to growth and development.

4. **Statement 4**: Florigen is transported to the bud through the phloem.
- This statement is incorrect. Florigen is believed to be transported via the xylem, not the phloem.

**Hint:** Remember the functions of xylem and phloem in plant transport systems.

### Step 3: Identify the Incorrect Statement
After analyzing all statements, we find that Statement 4 is incorrect because it misidentifies the transport tissue for Florigen.

### Conclusion
The statement that is incorrect with respect to photoperiodism is: "Florigen is transported to the bud through the phloem."

### Final Answer
The incorrect statement regarding photoperiodism is that "Florigen is transported to the bud through the phloem."

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