Phycomycetes (Algal fungi) - Practice Questions & MCQ

• Phycomycetes include lower fungi or algal fungi.
• They occur in aquatic habitats, moist decaying wood and as obligate parasites on plants.
• Mycelium is branched filamentous and aseptate. It is a coenocyte.
• Mycelium of Phycomycetes is aseptate i.e. partitioning walls are absent and coenocytic i.e.they have multiple nuclei.
• The cell wall of Phycomycetes is cellulosic. That is why they are known as algal fungi.
• Sexual reproduction is by isogamy, anisogamy or oogamy. In isogamy, similar types of gametes are formed. In the case of anisogamy and oogamy, the two gametes formed are different from each other as the male gamete is smaller while the female gamete is larger.
• The result of sexual reproduction is zygospore which soon undergoes meiosis.
• Fruiting bodies are not found in members of Phycomycetes.

Examples of Phycomycetes:
1. Phytophthora infestans- causes late blight of potato and tomato. Blight refers to brown to black dead areas on the tissue. The Irish famine of 1845-47 was a result of late blight potato.
2. Albugo candida- Causes white rust in crucifers. It is characterized by white blisters on leaves and stems.
3. Pythium debaryanum- Causes damping off.
4. Sclerospora graminicola and Peronospora parasitica cause downy mildew in cereals and other plants respectively.
5. Rhizopus stolonifer- also called black bread mould and bread fungi. It causes soft rot of strawberry, apple, sweet potato etc.

6. Pilobolus- Dung fungi