Which is incorrect about phycomycetes ?

Options

A. Mycelium is aseptate and coenocytic
B. A zygospore is formed by fusion of gametes
C. Asexual reproduction takes place by motile aplanospores and non-motile zoospores
D. White spots seen on mustard leaves are due to parasitic fungus Albugo

Answer

To determine which statement about phycomycetes is incorrect, we need to analyze each of the provided statements one by one.

1. **Mycelium is aseptate and coenocytic.**
- Phycomycetes, also known as lower fungi, typically have a mycelium that is aseptate (lacking septa or cross-walls) and coenocytic (multinucleate). This statement is correct.

2. **Azygospore is formed by fusion of gametes.**
- Azygospore is a type of spore that is formed through the fusion of gametes in certain fungi, including some phycomycetes. This statement is also correct.

3. **Asexual reproduction takes place by motile epilospores and motile spores.**
- Phycomycetes reproduce asexually through structures like zoospores, which are motile. However, the term "epilospores" does not accurately describe any known reproductive structure in phycomycetes. This statement is incorrect.

4. **The spots seen on mustard leaves are due to the presence of parasitic fungus.**
- This statement is generally true as certain fungi can cause spots on plants, including mustard leaves, indicating a parasitic relationship.

Based on the analysis, the incorrect statement about phycomycetes is the third one regarding asexual reproduction.

### Final Answer:
The incorrect statement about phycomycetes is: "Asexual reproduction takes place by motile epilospores and motile spores."