Topic 5 - Kingdom Fungi

The study of fungi is called mycology

Characteristics
-found in moist,wet places
- have chitin cell walls
- store energy as glycogen (like animals)
- are decomposers

Structure
- some are unicellular (yeast)

 Electron microscope image of budding yeast

- most are multicellular - the cells line up to form hyphae (gombafonalok) and the hyphae branch and form mats, which are called mycelia (gombafonadékok)

 Light microscope image of mold (penész) mycelia

Nutrition

- heterotrophs : most are saprotrophs (they recycle nutrients), 

                          some are parasites (they have specialized hyphae, which grow into their host, these are called haustoria), 

                          some are mutualists (2 typical examples are mycorrhiza (fungi and plant roots) and lichens (fungi and cyanobacteria or green algae))

-extracellular digestion

Reproduction

Asexual: 

1) Fragmentation (breaking of hyphae)

2) Budding (found in yeast)

3) Asexual spores on sporangia

Sexual:

2 different (+ and -) hyphae meet, they fuse and a sporangium grows at this point.  Sexual spores form on this sporangium, they are highly resistant. 

Classification

1.  Zygomycetes (moszatgombák)

- examples are black bread mold and peronospora

Black bread mold (Rhizopus)

Peronospora on a grape leaf

- no branching of hyphae

-mostly saprotrophs (peronospora is one of the few parasites)

-will reproduce asexually if there is enough water and food

-if water or food is limited, then they will reproduce sexually, to produce resistant sexual spores, which are called zygospores

 

2. Ascomycetes (tömlős gombák)

-these are also called sac fungi

-some are unicellular (yeasts), others are multicellular with branching hyphae (mycelium)

-the sexual spores (ascospores) are found in sac-like cases called asci (ascus is the singular)

-this is the largest group of fungi with the most variablility

-examples include: yeast (élesztők)

penicillium (from which the antibiotic, penicillin, was derived)

ergot

powdery mildew (lisztharmat)

cup fungi (csesze gomba)

morels (kucsma gomba)

3.  Basidiomycetes (bazídiumos gombák)

-examples include:

mushrooms (kalapos gombák)

puffballs (pöfetegek)

bracket fungi (tapló gombák)

rusts

smuts

-sexual spores (basidiospores) are found in the basidium (sporangium), usually in the cap of the fungus, on the gills (lemezek)

-there is no asexual stage in this group

Lichens (zuzmók)
- an obligate symbiosis of fungal mycelia and cyanobacteria or green algae
- the fungal mycelia:

provide a structure that secures the lichen to a surface

 prevents the photosynthetic partner from drying out

uptake water and minerals from the environment

- the cyanobacteria or green algae:

photosynthesize

-can be red, yellow, orange, grey or black

-they can be crusty, foliose, shrubby
- only reproduce asexually
- classification unclear (neither really fungus, nor algae, nor bacteria!)

-they are pioneer species:  first to enter an uninhabited area (wide range of tolerance), slowly break down rock (acid production, mycelia boring into cracks, create humus when they die)

-they are indicator species: they are very sensitive to chemical pollution, eg. sulphur dioxide