div 1 exam 2

Fungi definition

Eukaryotic, spore producing, achlorophyllous

Organisms traditionally referred to as fungi

Not closely related

Vegetative growth

Hyphae, mycellium

Nutrition

Heterotrophic absorbers

Saprophytes, parasites, mutualistic symbionts

Glycogen

Plasmogamy

Fusion on prtoplasts

Karyogamy

Fusion of nuclei

Sexual reproduction (fungi)

Plasmogamy

Karyogamy

Meiosis

Formation of specialized spores

How long have fungi been around?

500Ma-1bn

Earliest fungi

Single celled and aquatic producing motile asexual spores

Zoospores

Aquatic producing motile sexual spores

Microsporidia

Placed among early diverging branches (non-motile)

Chrytridiomycota

Predominantly aquatic

1000 spp

Coenocytic mycelium

Zoosporic dissemination phase

Evolution of land dwelling fungi

Transition estimated around 700 Ma

Zoopagomycota

Motile spores replaced by thick walled zygospore

Mostly saprotrophs or parasites of metazoans, amoebae, other fungi

Mucoromycota

Terrestrial

500spp

Mainly saprobes

Coenocytic mycelia

Characterized by thick walled resting spore (zygospore (sexual) and columella)

Asexual reproduction by Sporangiospores

Homothallism and heterothallism

Ascomycota (sac fungi)

Largest group of fungi

80000 spp

Mycelium septate but functionally Coenocytic

Many dimorphic, homo and heterothalic

Asexual profiles (conidia)

Basidiomycota

Most familiar

32000 spp

Central role in decomposition of plant litter

Mycelium septate, clamp connections

Asexual propagules (conidia)

Rust fungi (teliomycetes)

8000 spp

Plant pathogens

No Basidiocarp

Big economic importance

Life cycles complex and constant challenge to plant pathologists

Heteroecious, autoecious

Puccinia graminis

Basidiomycota subphyla

Agaricomycotina

Ustaginomycotina

Pucciniomycotina

Wallemiomycotina

Agaricomycotina

Mushrooms, puffballs, shelf fungi, jelly fungi

Ustilaginomycotina

Smut fungi and allied taxa

Pucciniomycotina

Rust fungi and allied taxa

Rizomorphs

Hypahe lying parallel to each other and sometimes enveloped in sheath (cortex)

Primary mycelium

Homokaryon

Short lived

All nuclei identical

Results from germination of basidiospore

Secondary mycelium

Heterokaryon/dikaryon

Long lived

Results from plasmogamy

Characterized by clamp connections in many taxa

Tertiary mycelium

Represented by organized specialized tissues that make up the basisiocarp

Basidioles

Cells resembling basidia that have not produced basidiospores

Hermaphroditic

Every thallus bears both male and female organs that may or may not be compatible

Dioecious

Some thalli bear only male or female organs (very few discovered)

Sexually undifferentiated

Sexually functional structures are produced that are morphologically indistinguishable as male/female (vast majority)

Dacrymycetes

Mostly jelly like causing mainly brown rot

Tremellomycetes

Jelly fungi but also contains yeasts and dimorphic taxa

Teliospore

Site of Karyogamy

Technically part of the basidium

Promycelium

Site of meiosis and formation of sterigmata and basidiospores

Stage 0

Spermogonia bearing spermatia (n)

Stage 1

Aecia bearing Aeciospores (n+n)

Aeciospores

Infect primary host (produced on alternate host)

Stage 2

Uredinia bearinf urediniospores

Urediniospores

Reinfect primary host

Amplifies disease within primary host

Stage 3

Telia bearing Teliospores

Teliospores

Final stage on primary host

Overwinters as diploid

Stage 4

Basidia beating basidiospores

Basidiospores

Infect alternate host

Ustilaginales

No sex organs

Monokaryons nonpathogenic

Dikaryon pathogenic

Heterothallic

Teliospores

Karnal bunt

Karnal, India 1931 - minor disease in India until 1970s

1972 reported in Mexico

By 1972 many countries established quarantines to prevent introduction

USA in 1981 (quarantine)

Mycelial ascomycetes

Compartmentalized mycelium

Septa with simple pores (dolipore in basidios)

Presence of woronin bodies

Chestnut blight

1905 Bronx

Before disease dominant tree in eastern hardwood forest

Only tree used for telegraph poles railroad ties

Cryphonectria

Introduced from Japan

50 years 3.6 mil acres

Cryphonectria somatic structures

Simple pores

Woronin bodies

Concentric bodies

Ascophaerales

Sometimes classified with yeasts due to lack of ascocarp developed from outgrowths of hypahe

Apothecium

Hymenium - layer of asci lining the surface of the disk

Composed of cleavage of cylindrical asci

Paraphyses

Excels is fleshy part of ascocarp

Unitunicate-operculate

Only in apothecial advocates

Unitunicate-inoperculate

No operculum but special elastic ring mechanism

Perithecial and some apothecial ascocarps

Protounicate

No active spore shooting mechanism

Mainly in cleistotheci

Bitunicate

Double wall

Diverged long ago

Anamorph

Asexual

Imperfect

Conidia

Mitospore

Teleomorph

Sexual

Perfect

Ascospore

Meiospore

Umbilicate

Foliose lichen thallus that is attached at a single point

Gelatinous lichens

Thalli usually contain cyanobacteria

Rhodophyta

Monophyletic Clade in archaeplastida (has chloroplast

Only chlorophyll a

Outcrop to viridiplante

Viridiplante

Monophyletic

Green algae and land plants

Chlorophyll b

True starch

Andreaeopsida

Granite mosses

Sphagnopsida

Peat mosses

Bryopsida

True mosses