Kingdom Fungi

Mushrooms, mould, and mildew

Fungi in action

Characteristics of Fungi In partners or as a group – what

characteristics define a fungus (pl)?

If you said:

Eukaryotic

Heterotrophic, but do not have an internal digestive system (have external digestion)

Non vascular (no root system)

Reproduce sexually and asexually

You’d be right!

Wait...Fungi aren’t plants?Plants

Have a root system

Autotrophs

Cell wall composed of cellulose

Fungi

Non-vascular system

Heterotophic

Cell wall is composed of chitin

Structure of FungiSome fungi are

single-celled

They are called yeasts

Valuable economically – can you think why?

Structure of FungiMost fungi are

multi-cellular

Body of a fungi generally occurs below ground

Body = mycelium = a branching, mesh-like network of hyphae

Structure of Fungi cont.An individual filament is called a

hypha (hyphae (pl))

One long continuous multicellular structure

Structure of Fungi cont. So what is a

‘mushroom’?

It is the spore producing reproductive structure of a fungus, which is called the fruiting body

Made of hyphae that are densely packed together

Fungal NutritionFungi release enzymes into their

surrounding

Enzymes break down the food externally

Fungi then absorb the nutrients that have been released by the enzymes through its cell membrane

One way of classifying fungi is through the four different ways that they obtain nutrients

Fungal Nutrition1. Parasitic

Fungi absorbs nutrients from the living cells of a host organism

Results in death of the host

Fungal Nutrition2. Predatory

Soil fungi whose mycelia have specialized structures for trapping prey

Fungal Nutrition3. Mutualistic

Fungi that have partnerships with other organisms (e.g. Plants, protists or animals)

Both organisms involved in the partnership benefit from the relationship

Fungal Nutrition4. Saprobial

Fungi that feed on dead or decaying organic matter

i.e. They are decomposers

Very important in nutrient recycling

Learning CheckWhat is mycelium and where is it

found?

When you see a mushroom growing from a dead log, which part of the fungus are you observing?

Fungal Classification 5 Major Phlya

Phylum Chytridiomycota (chytrids)

Phlyum Zygomycota (zygomycetes)

Phylum Deuteromycota

Phylum Ascomycota (ascomycetes)

Phylum Basidiomycota (basidiomycetes)

Based on differences in reproduction and the structure of the fruiting body they produce

Fungi Imperfecti (Deuteromycota)

Not known to reproduce sexually

Generally types of moulds

E.g. Penicillium mould; mould in blue cheese

Chytrids (P. Chytridomycota) Mostly unicellular

Aquatic species (marine or freshwater)

Spores have flagella (motile)

Parasitic or saprophytes

Zygospore Fungi (P. Zygomycota) Multicellular and mostly terrestrial (soil)

Include familiar bread and fruit moulds

Generally reproduce asexually

Zygospore Fungi (P. Zygomycota) Reproduce sexually in

unfavourable conditions to produce zygospores

Diploid structure (2n) that develops after two haploid (n) hyphae of opposite types combine their nuclei. Thick wall develops around nuclei to protect it.

Sac Fungi(P. Ascomycota) Largest fungi group

Develop small finger-like sacs called asci (contain spores) during sexual reproduction (similar to creation of zygospores)

Saprophyte and parasites

Includes yeasts, which reproduce by budding

Club Fungi (P. Basidiomycota) Includes ‘mushrooms’,

puffballs, and stinkhorns

Most are decomposers, some form symbiotic (mutualistic) relationship with plants

E.g. lichen

Club Fungi (P. Basidiomycota)

Fruiting bodies release spores called basidiospores from basidia (club-shaped hypha)

Reproduction Asexual

Budding – a smaller cell develops while attached to a parent cell. Eventually, small cell is pinched off of parent cell to produce a new individual

Reproduction Asexual

Fragmentation – a piece of mycelium breaks and forms a new individual

Spore production

Sexual reproduction - also involves spore production and often the creation of a fruiting body above ground

Fig3.21 (hand-out)

The Importance of Fungi Fungi are:

Decomposers – one of the most important groups for recycling materials along with Bacteris

Form symbiotic relationships – esp. with plants. Without these relationships plant growth and productivity would be reduced

Food source (e.g. Blue cheese, mushrooms) and used in food production (bread, beer)

The Importance of Fungi Fungi are:

Sources of antibiotics (medicine) (e.g. Penicillin). The discovery of antibiotics revolutionized health care worldwide.

Biocontrol – use fungi that target insects to control crop pests (e.g. Chinese caterpillar fungus; control of California potato beetles). This is cheaper and less damaging to the environment than using chemical pesticides

The Importance of Fungi Fungi

Cause animal and plant disease (e.g. Every year 10 – 50% of world’s fruit harvest is destroyed by fungi!) (e.g. Athlete’s foot, ringworm)

Food spoilage (mould)

Meet the worlds largest organism

http://www.scientificamerican.com/article.cfm?id=strange-but-true-largest-organism-is-fungus

Honey mushrooms – give an inkling of what is below.