KINGDOM FUNGI

DNA evidence now indicates kingdom fungi is more closely related to animals than plants!!!!

The Body of a Fungus Fungi exist mainly in the form of slender filaments (hyphae). – long chains of cells joined end-to-end divided by cross-walls rarely form complete barrier cytoplasm freely streams in hyphae – mycelium - mass of connected hyphae

General Characteristics – Fungi are heterotrophs. (Decomposers) – Fungi have cell walls that include chitin and not cellulose like plants do. – Chitin is also found in insects!!!

How Fungi Reproduce Spores most common means of reproduction – may form from asexual (mitosis) or sexual processes (meiosis) – most often dispersed by wind but some spread by insects or other small animals – Fungi are grouped by the way they reproduce

How Fungi Obtain Nutrients All fungi obtain food by secreting digestive enzymes and then absorbing the organic molecules produced (external digestion). – extensive hyphae network provides enormous surface area for absorption – many fungi able to break down cellulose in wood

Ecology of Fungi Fungi and bacteria are the principal decomposers in the biosphere. – mineral cycling Fungi are virtually the only organisms capable of breaking down lignin. Fungi often act as disease-causing organisms for both plants and animals. – agricultural damage – human health

Kingdom Fungi – you must know 4 Major Phyla 1.Phylum Zygomycota = the Bread Molds Rhizopus – black bread mold 2.Phylum Ascomycota = the Sac Fungi Yeast, morels, truffles 3.Phylum Basidiomycota = the Club Fungi Mushrooms, puffballs, bracket fungi, rusts, smuts, toadstools 4.Phylum Deuteromycota = the Fungi Imperfecti

-Regarded as imperfect because they exhibit no sexual stage has been observed in their life cycle - Members are not closely related and are not necessarily similar in structure or appearance; do not share a common ancestry, polyphyletic = coming from many ancestors – hmm weird Deuteromycota (Imperfect Fungi)

Deuteromycota – the Fungi Imperfecti Resemble Ascomycetes, but their reproductive cycle has never been observed Penicillium used to be imperfect but is not anymore!!! Different from Ascomycetes because there is a definite lack of sexual reproduction, which is why they are called Imperfect Fungi Penicillium fungi Up Close

-are primarily decomposers -asexual spores may be produced in sporangia -sexual reproduction occurs between + and – strains forming a 2n zygote; a zygospore develops and may lie dormant for a long period of time; meiosis occurs just before germination -only the zygote is diploid; all hyphae and asexual spores are haploid Zygomycota (Rhizopus) the Common Molds

Zygomycota – common molds The fungal mass of hyphae, known as the MYCELIUM penetrates the bread and produces the fruiting bodies on top of the stalks Mycelia = a mass of hyphae or filaments

Rhizoids = root-like hyphae The zhizoids meet underground and mating occurs between hyphae of different molds (SEXUAL REPRODUCTION)

Ascomycota Very large group including yeasts, common molds, and morels Named for reproductive structure ascus

Ascomycota Yeasts – unicellular - most reproduction is asexual and takes place by cell fission or budding ferment carbohydrates play a leading role in genetic research

Basidiomycota Most familiar fungi (mushrooms, toadstools, puffballs, rusts, and smuts) – named for characteristic sexual reproductive structure, basidium

Basidiomycete or Club Fungi

Basidiomycota

Bracket Fungi Puff Balls Mushrooms Jelly Fungi Basidiomycete Fungi that all produce Basiospores

Other Basidiomycetes Rusts and Smuts Rust infecting wheat leaves Rust infecting a Leaf Whitrot Smut digesting old wood

Lichens Lichens are symbiotic associations between a fungus and a photosynthetic partner. – usually ascomycetes Specialized fungal hyphae penetrate photosynthetic cells and transfer nutrients to fungal partner. – Durable fungus, combined with photosynthetic properties, has enabled lichens to invade harsh climates. – extremely sensitive to pollutants

Crustose Foliose Fruticose

Mycorrhizae “myco” = fungus and “rhiza” = root Symbiotic association between plant roots and fungi Several different types of association (defined by structure of fungus:plant interface)

Mycorrhizae The plant photosynthesizes while the fungus more efficiently takes up nutrients and water from the rhizosphere than the roots would alone. Plant benefits include: Improved nutrient/water uptake Improved root growth Improved plant growth and yield Improved disease resistance Reduced transplant shock Reduced drought stress