Mycology

Mycology- The study of fungi

Fungi Types • Saprophytes- an organism that feeds on dead organic

material or wastes

• Mutualists- an organism that lives with another

organism symbiotically (happily)

• Parasites- an organism that absorbs nutrients

from its host – these organisms sometimes create specialized hyphae to take

the host’s nutrients. These hyphae are called haustoria.

Mycology

Mycology- The study of fungi

Fungi Types

Fungi Characteristics

• live everywhere

• various shapes, sizes, colors

• grow anchored

• sexual & asexual reproduction through spores

• multicellular, eukaryotic heterotrophs (a few unicellular Ex: yeast)

• Saprophytic, parasitic, symbiotic varieties

• obtain food through extra-cellular digestion

food is digested outside the cells and then the digested products are absorbed

Fungi Structure • have threadlike filaments called hyphae

– Nonseptate (coenocytic) – no distinct cells, cytoplasm streams along the length of the filament

– Septate – divisions between cells (septa) with pores so cytoplasm still streams

• have mycelium- a network of hyphae which are specialized for different functions – Reproduction – fruiting body

– Food source

– Anchor the fungi

• have cell walls made of chitin

Fungi Structure

Fungi Reproduction Asexual Reproduction

• Fragmentation- broken off pieces of hyphae grow into new mycelia

• Budding- a new individual pinches off from the parent, matures, and separates from the parent.

• Spores- spores are reproductive cells that can grow into a new organism (sporangiospores); produced by mitosis – Spore Advantages

• usually produced by a sporangium for added protection

• spores are small, lightweight and easy to scatter

• large numbers are produced to ensure survival

Fungi Reproduction Sexual Reproduction

2 haploid nuclei fuse to create a diploid structure

- opposite mating types

- dikaryotic structure 2 haploid nuclei remain

separate (heterokaryotic)

- the fusion of the hyphae is called plasmogamy

- haploid spores produced by meiosis

- haploid nuclei fuse to create a diploid structure in a process called karyogamy

Fungi Reproduction

Fungi Reproduction

Deuteromycotes • only able to reproduce asexually and

therefore called fungi imperfecti

• used in food production (soy sauce, blue

cheese)

• being reclassified

• Ex: Penicillium

Chytridiomycetes

Chytrids – Primitive Fungi

- Microscopic

- Unicellular

- Nonseptate

- Aquatic varieties

- Powerful decomposers

- Produce zoospores (flagellated spores) and

gametes

Chytridiomycetes

Chytrids – Primitive Fungi

Zygomycotes (Bread Molds) • Can reproduce asexually by spores

• Can reproduce sexually

– by combining gametangium to produce a zygospore that

can resist harsh conditions

– zygospore produces a sporangium

• Grow Specialized Nonseptate Hyphae

– stolons = horizontal hyphae that make up the mycelium

– rhizoids = hyphae that penetrate the food and anchor the

mycelium; secrete digestive enzymes

• Ex: Rhizopus

Zygomycotes (Bread Molds)

Ascomycotes (Sac Fungi) • Sexual Reproduction

– develop sexual spores in saclike structures called ascus (asci); the spores are called ascospores

• Asexual Reproduction – chains or clusters of asexual spores called conidia develop from

elongated hyphae called conidiophores

• Ex: morels, truffles, baker’s yeast, Aspergillus, Ergot

Ascomycotes (Sac Fungi)

Ergot

Truffles

Ascomycotes (Sac Fungi)

• Have club shaped hyphae called basidia

that produce spores called basidiospores

• Many produce deadly toxins

Ex: mushrooms, puffballs, shelf fungi,

smuts & rusts

Basidiomycotes (Club Fungi)

Basidiomycotes (Club Fungi)

Basidiomycotes (Club Fungi)

Glomeromycetes • Newest group

• Nearly all are arbuscular mycorrhizae

– Estimated 90% of all plants have a mutualistic

relationship with one of these fungi types

Mycorrhizae

Mycorrhizae- a symbiotic relationship where a

fungus lives with plant roots.

- Fungus- helps to provide nutrients to the plant

- Plant- provides AA and sugars to the fungus

Ectomycorrhizal fungi – wrap around roots, but do

not penetrate the plant body

Endomycorrhizal fungi (arbuscular) – penetrate the

plant roots

Endomycorrhizal Fungi

Endomycorrhizal Fungi

Ectomycorrhizal Fungi

Ectomycorrhizal Fungi

Mycorrhizae

Mycology

mycorrhizae

lichens

Lichens

Lichens- a symbiotic relationship between a

fungus and an autotroph such as green algae.

- Fungus- provides H2O, minerals & protection

- Autotroph- provides food for both organisms

Asexual Reproduction by fragmentation

- fragments called soredia

Sexual Reproduction by spores & stealing algae

Lichens

Lichens

Fungi Reproduction

Fungi Reproduction

Fungi Reproduction