Kingdom Fungi

Fungi In The Scheme Of Life Animalia Plantae . Protista Monera

Why Fungi Are Important Important as decomposers Spoil food Produce antibiotics Cause disease in plants

Why Fungi Are Important Cause disease in animals (Athletes foot, yeast infections, etc.) Poison humans and animals Important food source Produce important fuels and industrial chemicals (ie. ethanol)

During the American Revolution (1775-1783), more British ships were destroyed by wood-digesting fungi than by enemy attack.

Fungal Characteristics Eukaryotic Multicellular (with one exception) Heterotrophic Absorb nutrients - may be saprobes (absorb from dead material), parasites, or mutualistic symbionts (with algae make lichen).

Fungal Characteristics Secrete powerful enzymes Cell walls contain chitin, a polysaccharide also found in arthropod exoskeletons Lack flagella

Vegetative body consists of mycelia made up of networks of hyphae The Body Plan of Fungi Vegetative body consists of mycelia made up of networks of hyphae Hyphae - Long threads of cells designed to maximize surface area and also transport nutrients

Hyphae Hyphae are designed to increase the surface area of fungi and thus facilitate absorption May grow fast, up to 1 km per day, as they spread throughout a food source In some fungi the cytoplasm in the hyphae are not divided by cell walls. This continuous cytoplasm contains several nuclei. In other fungi septa may be present. Septa partly divide the hyphae into compartments but the cytoplasm can still flow moving nutrients through out the fungus

Hyphae Pores Septa No Septa

Classification of Fungi Classification of fungi is based on life cycle, specifically reproductive structures. Fungi can reproduce both sexually and asexually by means of spores There are three major phyla of fungi, classified by their pattern of sexual reproduction. These are the conjugation fungi, the sac fungi, and the club fungi. A fourth phylum called the imperfect fungi includes thousands of fungi where their sexual reproduction pattern is unknown.

Zygomycota (Conjugation Fungi) Zygomycota - Zyg = yolk - Zygote forming fungi. Eg. Rhizopus (common bread mould) About 600 described species Mostly terrestrial Root like hyphae, called rhizoids, anchor the fungus, secrete digestive enzymes, and absorb nutrients.

Zygomycota (Conjugation Fungi) Other hyphae, called stolons, grow in a network over the surface of the food. Give rise to sporangiophores, which are the reproductive hyphae.

Zygomycota (Conjugation Fungi) Usually reproduce asexually by spore formation. Conjugation occurs when hyphae of different strains touch. The hyphae swell and produce a gamete-producing structure. The wall between the two hyphae break and the nuclei fuse to form a number of diploid (2n) nuclei. Forms a zygospore which allows the fungus to survive harsh environmental conditions. Will grow again when conditions are favourable.

Ascomycota (The Sac Fungi) Ascomycota - Asc = sack - Truffles, yeasts, powdery mildew, morels & cup fungi. Largest group of fungi All are multi-cellular with the exception of yeasts.

Ascomycota (The Sac Fungi) Hyphae have septa. Sac Fungi produce two kinds of spores : Sexual spores – ascospores Asexual spores – conidia Ascospores develop within a saclike ascus.

Ascomycota (The Sac Fungi) The visible portion of the fungus is the fruiting body which contains the spore bearing sacs (asci). Beneath the surface is a large mycelium. Some members of this group cause plant diseases.

Basidiomycota (The Club Fungi) Basidiomycota - Basidium = club About 25,000 described species including mushrooms, toadstools, puffballs, rusts and smuts. Important decomposers of wood because of their ability to hydrolyze lignin

Basidiomycota (The Club Fungi) The fruiting body only grows when conditions are favourable. The main part of this fungus is the mycelium which grows underground. The largest living organism in the world is a club fungus (a honey mushroom) in Oregon. It’s mycelium covers an area of about 2200 acres; the size of 1220 soccer fields.

Basidiomycota (The Club Fungi) Asexual reproduction is uncommon Sexual reproduction produces basidiospores which are produced in the fruiting body or “club” of the fungus.

Basidiomycota (The Club Fungi) The mushroom consists of a stalk and a cap. The undersurface has many “gills” that are made up of hyphae. Each gill has many basidia where the spores are produced.

Basidiomycota (The Club Fungi) Many types of mushrooms are edible but many are also extremely poisonous. There are three main species of wild mushrooms which can be harvested in Saskatchewan: morels, chanterelles and pine mushrooms. Since the different species are harvested at different times, these wild mushrooms can be harvested throughout the growing season. Make sure you are able to positively identify any wild mushroom you find before eating it as it may be your last meal !!!!

Chanterelles

Pine Mushroom

Deuteromycota (Imperfect Fungi) Deuteromycota - Deuter = second - The imperfect fungi These organisms exhibit all the characteristics of fungi, but have not been observed reproducing sexually As classification is based on sexual reproduction, Deutoeromycetes cannot be definitively placed in any phylum

Deuteromycota (Imperfect Fungi) Beneficial - Pennicillium Harmful – Athlete’s foot

Lichens Lichens – Symbiotic relationship between fungi and algae. Over 25,000 species described. Some lichens are estimated to be more than 4500 years old. Ascomycetes are usually the fungal component although some basidiomycetes lichens are known. Hyphae account for most mass. Fungus provides moist environment protection, support and minerals. Algae provides fixed carbon (photosynthesis).

The End