Kingdom Fungi

Fungi & Molds

• Fungi Are eukaryotic heterotrophs.
• Frequently decomposers, sometimes parasites.
• Usual structure is a mass of entangled filaments called Hyphae
• Hyphae can have cross walls (Septum) separating individual cells. Or have no separations.
• Overall mass is called mycelium

Mushroom showing mycelium & hyphae

Reproduction:

• Fungi differ from many organisms in that they:
• Reproduce sexually & asexually
• Longest stage of life cycle is in the haploid (N) stage NOT the diploid (2N) stage.
• Asexual reproduction is accomplished through the creation and spreading of asexual spores.
• Sexual reproduction is accomplished through creation and spreading of sexual spores by opposite mating types ((+) & (-)).

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Divisions:
There are 3 major divisions of fungi - Based on Characteristics of sexual spores and fruiting bodies
Division Zygomycota:

• Example: Black Bread mold
• Hyphae produce Sporangium which form spores asexually which are released to form new mycelia.
• Reproduce sexually also.
• Hyphae of (+) and (-) mating types called Gametangia fuse to form a diploid (2N) Zygospore
• Zygospore undergoes meiosis to produce spores which are then released

Life Cycle of Bread Mold

• Sexual reproduction (see fig. 19-6, pp. 410 in text)
• Hyphae called Stolons of opposite mating types (+ & -) will fuse to form a structure called Gametangia.
• Diploid (2N) Zygospore is formed.
• Zygospore produces sporandia which undergoes meiosis to release haploid (N) spores.

Division Ascomycetes (Sac Fungi)

• Named because sexual spores are produced in small sacs called asci (ascus).
• Asexual spores are produced on conidia by special hyphae called conidiophores.

Life cycle of an ascomycete

Division Basidomycota:

• Include mushrooms, shelf fungi & puffballs

Examples of division basidomycota

• Name derives from formation of a transient diploid (2N) stage of the life cycle called the Basidium.

Life cycle of basidiomycota

NOTE: NEVER eat a wild mushroom. Many are extremely toxic and can cause serious injury or death if eaten.

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Ecological Significance:

• Are valuable decomposers which function to return organic material back to the ecosystem.
• Fungi can form valuable symbiotic relationships
• Example are lichens which is a symbiotic relationship with algae.

lichens

• Have great economic value
• Yeast is a unicellular fungus used for baking and brewing.
• Many mushrooms are edible

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Diseases caused by fungi.

• Plants are most vulnerable to molds & fungi.
• It is a serious threat to agriculture some common crop diseases caused by molds & fungi are:
• Potato blight
• Wheat rust
• Corn smut
• Can cause disease in humans.
• "Athlete's foot"
• Ring worm
• Thrush and other yeast infections