Diversity of Fungi
Diversity of Fungi
I. Intro and General biology
A. Defining fungi
B. Feeding strategies
C. The fungal body
II. Fungal diversity – (table 31.1)
A. 4 phyla
III. Fungal associations
A. Mycorrhizae
B. Lichens
Fungi are our relatives
Fungi
Breathe in….
Common Ancestor
The world’s biggest and oldest
organisms?
Armillariella - a fungus found in Michigan
40 acres
‹ 1500 years old
‹ 100 tons
‹
General Biology of the Fungi
What are fungi?
‹
Heterotrophic
 Energy, carbon, nutrients from food
=
1
General Biology of the Fungi
What are fungi?
What are fungi?
Heterotrophic
‹ Absorptive nutrition –
 Secrete digestive enzymes into
environment
 Absorb the products
‹
General Biology of the Fungi
They may be eat dead or
living food.
Saprobes eat dead stuff
Carbon cycle
General Biology of the Fungi
Some are even predators!
Nematode
General Biology of the Fungi
Fungi
Heterotrophic
‹ Absorptive nutrition
‹ Chitin in cell walls
 Structure
 Who else has chitin?
‹
Infectious parasites
• Most AIDS patients die of
fungal infections
• Ringworm, athlete’s foot,
• Valley Fever
General Biology of the Fungi
The fungal body
• Some fungi are unicellular.
‹
Yeasts
2
General Biology of the Fungi
The fungal body
• Mycelium – the vegetative/feeding body
• Hyphae – tubular filaments
No
walls
Septa –
incomplete
walls
General Biology of the Fungi
The fungal body
• Hyphae give them a large surface
area–to–volume ratio
High SA:Vol
Low SA:Vol
Good for digesting and absorbing their environment
General Biology- Reproduction
• Fungi reproduce asexually or sexually
• Sexually:
Mating types (NOT male and female)–
2 or more Genetic types that have to
mate with another type
NOT a morphologic distinction (like
male/female)
Diversity in the Kingdom Fungi
• There are 4 fungal phyla
• Sexual reproduction is a distinguishing feature
General Biology - Reproduction
Dikaryon – hyphae with 2
genetically different nuclei
• Have a haploid (n)
diploid (2n) and
dikaryon (n+n)
• The cells fuse, but not the
haploid nuclei.
Diversity in the Fungi: Chytrids
• Flagellated spores and gametes
• Resemble the ancestral fungi
• Aquatic organisms
3
Diversity in the Fungi:
Zygomycetes
• Hyphae undivided into cells grow around
exploring and digesting.
• Dispersal - a stalk with a spore sac.
Diversity in the Fungi:
Ascomycetes
• Hyphae are segmented
BUT fluid and even nuclei can move
through separations.
• Ascus – reproductive structure.
(contains ascospores)
Diversity in the Fungi:
Ascomycetes
Filamentous and produce cup
shaped fruiting structures
with the asci on them.
Diversity in the Fungi:
Zygomycetes
• No fruiting body
• Mating types grow together,
form a zygosporangium
(gamete sac)
• The only diploid cells are the
zygotes in the zygosporangium.
• Meiosis Æ spores
Diversity in the Fungi:
Ascomycetes
Some are unicellular (like brewer’s yeast)
Why are the ascomycetes my favorite
fungi?
Yeast metabolizes glucose into ethanol and C02.
Diversity in the Fungi:
Basidiomycetes
• Hyphae have partitions with small,
distinctive pores.
• Basidia - sexual reproductive structure
4
Diversity in the Fungi:
Basidiomycetes
Reproduction:
• Hyphae fuse to form dikaryon.
• Basidiocarp = fruiting structure
(mushroom)
• Basidia develop on the gills.
• Haploid spores are made in the basidia.
Fungal Associations
• Mutualism
Diversity in the Fungi:
Imperfect Fungi
How do we classify the 4 phyla?
By Sexual Reproduction Methods and Structures
Imperfect fungi – fungi that cannot be classified
Fungal Associations
Mycorrhizae
associations of fungi with plant roots
relationship where both partners benefit
Important for plant establishment
• Symbiosis
living together in a prolonged ecological relationship
Plant gets?
Fungus gets?
Lichen Anatomy - Figure 31.18
Lichen
NOT a single
organism!
A meshwork of a fungi and a
photosynthetic microorganism (green
algae or cyanobacteria)
5
Lichens
Review of Fungi
Are they mutualisms?
When associated, the algal cells:
1. Leak more
2. Grow slower
So, is the fungus a parasite?
Associated
Not - Associated
•
•
•
•
Sister group to animals
Digest and slurp up food outside their bodies
Unicellular or filaments
Important symbiotic relationships:
‹ Mycorrhizae
‹ lichens
Review of Fungi
There are 4 fungal phyla:
• Chytrids only fungi with flagella
• Zygomycetes Make Zygospores
• Ascomycetes Make asci. Cup fungi and
brewer’s yeast
• Basidiomycetes Make basidium.
mushrooms
6