The phytochrome was discovered by

Options

A. Garner and Allard
B. W. Went
C. F.F. Blackman
D. F.E. Fritsch

Explanation

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks who discovered phytochrome.

2. **Recall the Scientists**: From the information provided, we need to remember the names of the scientists associated with the discovery of phytochrome.

3. **Mention the Scientists**: The scientists who discovered phytochrome are Garner and Allard.

4. **Contextualize the Discovery**: It is important to note that this discovery was made in the context of the tobacco plant.

5. **Define Phytochrome**: Phytochromes are light-sensitive pigments in plants that act as photoreceptors, meaning they can detect different wavelengths of light.

6. **Explain the Types of Phytochrome**: Phytochromes are divided into two types:
- **PS1**: Sensitive to light at a wavelength of 700 nanometers.
- **PS2**: Sensitive to light at a wavelength of 680 nanometers.

7. **Conclude the Answer**: Therefore, the correct answer to the question is that phytochrome was discovered by Garner and Allard.

**Final Answer**: The phytochrome was discovered by Garner and Allard in the tobacco plant.

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