Role of tapetum was discovered by

Options

A. Flemming
B. Ubisch
C. Strasburger
D. Nawaschin.

Answer

To determine who discovered the role of tapetum, we can analyze the options provided:

1. **Fleming**: He is known for characterizing animal mitochondria in 1882. His work is primarily related to cytogenetics and does not pertain to the tapetum. Therefore, this option is incorrect.

2. **Juwisch**: Juwisch is recognized for discovering orbicules, also known as Juwisch bodies, which are secreted from the tapetum. He explained the role of the tapetum in the formation of the exine, which is a critical component of pollen grains. This indicates that Juwisch is indeed associated with the study of the tapetum.

3. **Strasburger**: He is known for his work on Monotropastrum humile, where he observed the fusion of male and female gametes, leading to the discovery of syngamy. His research does not focus on the tapetum, making this option incorrect.

4. **Navashti**: He worked on Lilium and confirmed syngamy, also contributing to the concepts of triple fusion and double fertilization. His work is not related to the tapetum either.

Based on the analysis, the correct answer is **Juwisch**, as he discovered the role of the tapetum in the formation of orbicules and exine.

### Step-by-Step Solution:
1. **Identify the options**: Fleming, Juwisch, Strasburger, Navashti.
2. **Analyze Fleming's contribution**: Characterized animal mitochondria (not related to tapetum).
3. **Analyze Juwisch's contribution**: Discovered orbicules and their relation to the tapetum and exine formation (relevant to tapetum).
4. **Analyze Strasburger's contribution**: Known for syngamy and gamete fusion (not related to tapetum).
5. **Analyze Navashti's contribution**: Worked on Lilium and confirmed syngamy (not related to tapetum).
6. **Conclusion**: The role of the tapetum was discovered by Juwisch.