• Fungi

SULFUR SHELF FUNGUS Polyporus

BIG LAUGHING MUSHROOM Gymnophilus

PURPLE CORAL FUNGUS Clavaria RUBBER CUP FUNGUS Sarcosorna

TRUMPET CHANTARELLE Caraterellus

SCARLET HOOD Hygrophorus

The light red coral Fungus, Ramaria

The shelf Fungus, Polyporus

Fly Agaric mushroom, Amanita muscariaCauses hallucinations when eaten.

A.ocreataVery poisonous

Key Concepts:

• Fungi are heterotrophs• Fungi and bacteria are the decomposers of the

biosphere• Fungal enzymes are secreted outside their body

which digest food• Most fungi are multicelled• Fungal spores develop from hyphae• Many fungi are symbionts with other organisms

Characteristics of Fungi

• Premier decomposers• Heterotrophs• Extracellular digestion• Absorption of products• Saprophytic• Parasitic

Major Groups of Fungi

• Zygomycota• Ascomycota• Basidiomycota• Life Cycles

– Asexually most often• Spores• Mycelium

– Hyphae– Chitin

nuclear fusion meiosis

zygospore (2n)

spores (n) Zygospore Spore sac

mycelium develops from germinated spore

rhizoids

stolon

ASEXUAL REPRODUCTION

(mitosis)

contact between hyphae of two mating strains

germinating zygospore

Diploid StageHaploid Stage

young zygospore

gametangia fusing

50 µm

spores (n)

Spores and More Spores

• Sexual or asexual– Temperature

dependent– Moisture dependent

• Zygosporangium• Basidiospores• Ascospores

Sarcoscypha coccinia

ascospore (sexual spore)

spore sac

spore-bearing hypha of this ascoscarp

ascoscarp ascoscarp

conidia (chains of asexual spores)

budding yeast cell

Morels

Other Sac Fungi

• Molds– Penicillium

• Penicillin• Camembert and

Roquefort cheeses

– Aspergillus• Soy sauce• Soft drinks - citric

acid

• Yeasts– Saccharomyces

cerevisiae• Bread, wine and beer

– Candida albicans• Infections

Beneficial Associations Between Fungi and Plants

• Symbiosis– Mutualism

• Lichen– Fungus and

photosynthetic organism

Leaf-like

Old Man’s Beard Usnea

Erect branching LichenCladonia rangiferina

Lichens

dispersal fragment (cells of mycobiont and of photobiont)

cortex (outer layer of mycobiont)

photobionts

medulla (inner layer of loosley woven hyphae)

cortex

Other Symbiotic Relationships

• Mycorrhiza– Young tree roots– Mutualistic

• Fungi as clues to the environment– Decline correlate with rise in air pollution

• Fungi and disease– Histoplasmosis– Poisonings– Skin infections– Pneumocystis carinii

Athlete’s foot –Epidermophyton floccosum Apple scab- Venturia inaequalis

Reproductive structures of Pilobolus

Some Pathogenic and Toxic Fungi

ZygomycetesRhizopus - Food spoilage

AscomycetesAjeliomyces capsulatus- Histoplasmosis

Aspergillus – sinus, ear, lung infection

Microsporium sp. Various ringworms.

Verticillium sp Plant wilt

Monilinia fructicola- Brown Rot of Peaches

Basidiomycetes

Puccinia graminis Wheat Rust

Ustilago maydis Corn Smut

In Conclusion

• Fungi are heterotrophs and major decomposers• Most fungi are multicellular• The main groups of fungi are the Zygomycetes, the

Ascomycetes, and the Basidiomycetes• Fungi are classified by the type of spores they

produce

In Conclusion

• Most fungi can produce sexual and asexual spores• Lichen are mutualistic associations between a

fungus and a photosynthetic organism

• developed by M. Roig