Kingdom FungiThe Study of Fungi is called Mycology

What is probably the largest living organism on earth has been discovered in the Malheur National Forest in eastern Oregon. A fungus

living three feet underground is estimated to cover 2,200 acres. After testing samples from various locations, scientists say it is all one

organism.

Officially known as Armillaria ostoyae, or the honey mushroom, the fungus is 3.5 miles across and takes up 1,665 football fields. The small

mushrooms visible above ground are only the tip of the iceberg.Experts estimate that the giant mushroom is at least 2,400 years old,

but could be 7,200 years old.

Characteristics of Kingdom Fungi

• Be Multicellular• Have Eukaryotic cells• Be Heterotrophs • Must have cell walls

• Most fungi are sedentary..(they don’t move around, they live their lives anchored somewhere)

In order to belong to the Kingdom Fungi, organisms must:

Cell Walls• The cell walls of Fungi are

made of Chitin (Chitin is a sugar… the same substance

which makes up the exoskeleton of insects)

• Some fungi have cross walls, or septa, which divide the

filaments into compartments having a

single nucleus.

septum

Some cells lack septa and are multi-nucleated, or coenocytic

(have many nuclei)

• Digestion takes place outside the body (extra-cellular)

• Fungi are Absorptive Feeders …they simply ingest (absorb) digested foods

thru their cell walls

Facts• Fungi live and grow in their food

• only seen when the fruiting bodies emerge…. By then it’s too late

Facts• Cell Walls are either partial or

absent………. The cytosol is circulated through simple cyclosis.

Ecological Role• The major role of Fungi is as Decomposers (they are the great recyclers)…. They are Saprophytes

Fairy Ring

Fairy Ring

The Primary Structures of a Fungi

• Spores Hypha Mycelium Fruiting Body (haploid reproductive cell) (a single filament) (a mass of hyphae) (reproductive and

dispersion)

Spores: Haploid Reproductive Cells

Spore with Developing Hypha**(some fungi have haustoria, hyphae that can penetrate their host)

Spore

Hypha

The Hypha begins to branch as it digests its way through the food.

A Mass of Hyphae form the Mycelium

The Mycelium growth in a Petri Dish

Fungi spend most of their time as haploid (n) organisms. However, most form a temporary diploid structure for reproduction. The three

following stages occur during sexual reproduction…. plasmogamy, karyogamy and

meiosis.

Plasmogamy is the fusion of two haploid cells from two separate fungi strains. The

fusion forms a dikaryon (a cell with the two haploid nuclei). A hypha containing a dikaryon is called a dikaryotic hypha.

Karyogamy is the fusing of the two haploid nuclei of a dikaryon to form a single

diploid nucleus.

Meiosis of the diploid nucleus restores the haploid number.

2n

n

n

Fungi Reproduction

• Fungi reproduce both sexually and asexually.• Asexual reproduction includes: 1. fragmentation: the breaking up of hypha 2. budding: the pinching off of a small hypha outgrowth 3. asexual spores: there’s two kinds of asexual spores a. Sporangiospores are produced by sporangia which are located on top of a filament called a sporangiophore. b. Conidia are formed at the tips of specialized hyphae called conidiophores.

Asexual Spores

Sporangium:Produces the

sporangiospores

Sporangiophore:Holds up the sporangium

Asexual SporesThe Conidiophores look like tubes… the conidia look like

small black dots inside the tubes.

Classification of Fungimostly classified by the shape of the “Fruiting Bodies”The “Fruiting Bodies” are the reproductive structures.

• Phylum Zygomycota (bread mold)

• Phylum Basidiomycota (mushrooms, puff balls, bracket fungi)

• Phylum Ascomycota (cup fungi)

• Phylum Deuteromycota (Imperfect fungi)

Phylum ZygomycotaA common Zygomycota is Bread Mold

Hyphae lack septa

Sexual reproduction is by conjugation (fusing) hyphae from two different strains, followed by plasmogamy, karyogamy and meiosis and the production of Zygospores.

Zygomycota

Sporangium:Produces the spores

Sporangiophore:Holds up the sporangium

A nice bowl of mold

Want an orange ? Zygomycota does !!

Phylum Basidiomycota• Mushrooms

• Puffballs• Shelf (Bracket) Fungi

• Have Septa and reproduce sexually• Underground hyphae intertwine and grow upward to

produce a reproductive structure called a basidiocarp. This basidiocarp is what we call a mushroom.

• Basidiospores are produced on the basidia, reproductive structures, which are found on the edges

of the gills.

Agaricus (gills)Amanita phalloides “Death Cap”

Boletes: tubes instead of gills

Chanterelles: vase-shaped

Morels

Puff Balls

Shelf Fungi

Phylum Ascomycota

• Cup Fungi• Yeast

• Mildews

• The largest group of fungi • Named for the reproductive sacs or Asci that

form near the tips of the hyphae. Ascospores are formed here and released into the air when the ascus ruptures. These spores germinate to

form new hyphae.

Cup Fungi

Phylum Deuteromycota

• Athlete’s Foot• Ringworm• Penicillium

– Called “imperfect because a sexual reproductive stage has not been observed.

Penicillium: source of penicillin

Athlete’s Foot

Athlete’s Foot

Athlete’s Foot

Ringworm

Ringworm

Ringworm

Lichens

• symbiotic association held in a

hyphae mesh

alga provides food, fungus provides physical environment

•air pollution detection

Many Fungi are involved in Mycorhizzae relationships…Over 90% of plants have fungi associated with their roots. The fungus

absorbs and concentrates phosphates for delivery to the plant roots. In return, the fungus receive sugars synthesized by the plant.

The End