Introduction to the Fungi
Learning Objectives and
Disclosure Information
• Upon completion of this workshop, participants
should be able to:
• Set up a sampling station to collect airborne pollen and
fungal spore
• Recognize the most common types of pollen found in
the atmosphere
• Recognize the most common types of fungal spores
found in the atmosphere
• No conflicts to disclose
Fungi are eukaryotic
organisms that are
neither plant nor animal
Fungi include molds
Mushrooms
Puffballs
Bracket Fungi
Fungi can be unicellular such as yeast
Fungi usually have a thread like body
made up of hyphae
Hyphae make up the mycelium
Hyphae also make up the structure of
fruiting bodies such as mushrooms
Fungal Life Styles
• Fungi are absorptive heterotrophs
• As absorptive heterotrophs they exist as
– Pathogens
– Mutualistic symbionts
– Saprobes
Common Human Pathogen
Apple-Cedar Rust
A Destructive Plant Pathogen
Lichens are symbiotic organisms composed
of an alga and a fungus
The Majority of Fungi Are Saprobes
Most of the common airborne fungi are saprobes naturally
occurring on leaf surfaces, decaying plant material, or in soil
Fungi reproduce by spores
Spores can result from sexual
or asexual reproduction
Mycelium
Sexual Spores
Asexual Spores
Mycelium
Spore Release Mechanisms
• PASSIVE: Frequently related to wind speed and
turbulence – include members of the “Dry Air
Spora” which peak in the afternoon
• ACTIVE: Generally require moisture – common
mechanism for ascospores and basidiospores
– Basidiospores most abundant in predawn hours
– Ascospores most abundant during or following rain;
however, a number of ascospores only require high
humidity and are abundant in predawn hours
Types of Asexual Spores
Sporangium
Sporangiospore
or just “spore”
Conidia on hyphae
Conidium
Conidiophore
Sporangiophore
Rhizopus Sporangium
Chains of Conidia
ZYGOMYCOTA -- Zygospores
ASCOMYCOTA -- Ascospores
BASIDIOMYCOTA -- Basidiospores
ASEXUAL FUNGI -- Conidia - mold spores
Asexual Fungi
• Constitute an artificial group based only on
asexual spores
• Most are members of the Ascomycota with a
small percent members of the Basidiomycota
• Also called
–
–
–
–
–
Deuteromycetes
Imperfect Fungi (Fungi Imperfecti)
Mitosporic Fungi
Anamorphic Fungi
Mold Spores
Members of the Zygomycota produce
asexual spores in a sporangium
The zygospore (zygosporangium) is the
characteristic sexual structure of the Zygomycota
Characteristic sexual structure of the Ascomycota
is the ascus containing 8 ascospores
Ascomycota
• Many members of the Ascomycota
develop asci within a fruiting body.
• Fruiting bodies often called ascocarps
• Ascocarps can be
– Flask-shaped
– Cup-shaped
– Other
Cup-shaped fruiting body
Morels are also cup-shaped fruiting body
Asci with ascospores from a morel
Abundant Airborne Ascospores Following Rain
Airborne Ascospores Still in Group of 8
Basidiomycota
• The most conspicuous fungi in
the environment
• Basidiospores are typically
produced in a large fruiting
body such as
– Mushrooms
– Bracket Fungi
– Puffballs
Characteristic spores are basidiospores and four
basidiospores are produced externally on basidia
Basidia line the pores of bracket fungi
and the gills of mushrooms
Single Basidium with 4 Basidiospores
Basidiospores are small and single-celled
often with an asymmetric attachment peg
Rusts and Smuts
• Basidiomycota also includes two groups of
fungi that lack fruiting bodies
• Rust fungi and smut fungi
• Important pathogens on both native and
cultivated plants
Stem Rust of Wheat
Loose Smut of Wheat
Asexual Fungi