Mycology midterm exam

EFB 440 mycology at ESF

Subphylum Pezizomycotina

·        Functional sex organs

·        Incredible diversity

·        Ascogonium enclosed in an ascocarp (A p and C)

·        Mycelial or ascospore stage generally overwinters

saprobic or parasitic

most of ascomycretes

Eurotiales (Plectomycetes) order

·        Asci typically thin walled evanescent.

·        Ascocarps unicellular and reduced

·        Cleistothecium

·        Tolerant to very low amounts of water

·        Pathogens of animals

·        Producers of antibiotics and mycotoxins

·        Fermenter of food

sexual fusion involves trichogyne

on starchy and cellulosic substrates

Ascopharales order

lack of ascocarp

chalkbrood disease (kills larvae of a hive)

Onygenales order

Many medically important species

Characters

·        Free asci

·        Fusion of gametangial hyphae (no trichogyne)

·        Spherical to ovoid deliquescent melting spores

·        Single celles ascospores and dry conidia

·        Degrade KERATIN

(cool fungi on horse ram skull)

What is a trichogyne

a slender projection out of a ascomycete may serve as a fertilization tube of ascogonia and antheridia

What does deliquescent mean

melts away or dissolves easily

What does evanescent mean

thin walled and see through

What order is closely related to Eurotiales

Onygenales

What order of mushrooms does blue cheese and soy sauce originate

Eurotiales

Characteristics of the Pyrenomycetes

any ascomnycete with a perithecial

ovoid cylindrical unitunicate asci usually in hymenium

either shoot out of ooze out of perithecial

parasites of arthropods

endophytes

mycotoxin producers

mammalian parasites

model lab organism

EXAMPLE: Ergot, Epichloe

Name three tree and plant parasites

Cryphonectria, Nectria, Ophiostoma, Ergot, Epichloe

Order Discomycetes

apothecium

operculate and inoperculate varieties

composed of clavate or cylindrical asci with paraphases

Excipulum

What are paraphyses

spacer cells between the ascus in the ascomycetes

What are the two shapes of asci in an apothecium

clavate or cylindrical

What is an Excipulum?

the fleshy part of an ascocarp, holding the hymenial layer

What is the meaning of unitunicate-operculate and unitunicate-inoperculate?

unit- operculate = has a little opening on the top for spores to be releases (only in apothecial ascocarps)

unit- inoperculate = no operculum or opening but has a special elastic ring mechanism (found in perithecial and some apothecial ascocarps)

What are the four ascus types in ascomycetes

unit- operculate = has a little opening on the top for spores to be releases (only in apothecial ascocarps)

unit- inoperculate = no operculum or opening but has a special elastic ring mechanism (found in perithecial and some apothecial ascocarps)

Prototunicate = spherical and no active spore shooting mechanism (mainly cleistothecial ascocarps)

Bitunicate = Double wall, diverged long ago

Loculoascomycetes

bitunicate ascus, possibly most diverse ascomycetes, few studies, many plant and animal pathogens

What are the two patterns of development of conidia

Blastic — young conidium recognized before it is cut off by cross wall (budding)

Thallic — cross wall laid down before differentiation of conidium begins.

Two classes of asexual fungi anamorphs

Coelomycetes and Hyphomycetes

How many species of asexual fungi are there

2,000 described genera and 30,000 species

Characteristics of Coelomycetes

ONLY LIVING HOST (LEAVES, LIVING MATERIAL)

covered or ostiolate conidiomata

covered = acervulvus

usually develops within host

pressure of accumulating spores ruptures host epidermis1

What are the names used to describe the sexual asexual and combined fungi forms

anamorph = asexual (conidia, mitospores)

teleomorph = sexual (ascospores, meiospore)

holomorph = entire organism

Characteristics of coelomycetes

ostiolate conidiomata = pycnidia

flask shaped and lined on the inside with conidiophores

fungus provides enclosing wall

conidia ooze out through apical ostiole

Pycnidia def

an asexual fruiting body in an ascomycete lined with conidiophores.

Characteristics of hyphomycetes

ON JAM AND DEAD MATERIAL

exposed coniophores on conidiomata

usually solitary but can form

Columnar (syynnemata)

Cushion (sporodochia)

What are the two types of hyphomycete conidioma

columnar (synnemata)

Cushion (sporodochia)

Seven morphological groups of conidia

ameroconidia- single celled

Heliconconida- curved or coiled

Dictyoconidia- running 2 ways

Scolecoconidia- long, thin (worm- like)

Didymoconidia- 1 cross wall

Stauroconidia- radiating arms

Phragmo- rungs of a ladder

What is Conidiogenesis

1960s emphasized different techniques usedee to produce conidia

How do asexual fungi reproduce

the parasexual cycle

What are the steps in the parasexual cycle

through fusion or mutation obtain two nuclei in mycelium of fungus

fusion of the two nuclei (diploid 2n nucleus) (diploidization)

restoration of nuclei to their haploid state (haploidization)

• this process involves a series of atypical and irregular mitotic divisions of the 2nd nuclei

the cells then most likely have an odd number of chromosomes 2n+1 and 2n-1

then the 2n-1 might become haploid

What is required for the parasexual cycle

to have two types of nuclei in the mycelium of the fungus (heterokaryosis)

What is anastomosis

fusion of two of either the same or different mycelia hyphae

Why do daughter nuclei have an unequal number of chromosomes during the parasexual cycle

sister chromatids fail to separate during anaphase.

Compare and contrast the parasexual cycle and sex

parasexual cycle mimics similarities:

unlike hyphae may fuse

nuclei occupy same mycelium

Nuclei may fuse karyogamy to form zygote

genetic recombination may occur and diploid becomes haploid

Different:

mitotic divisions

incomplete ploidy levels

no meiosis

less genetic recombination

What are the nine generally recognized phyla

Opisthosporidia

Chytridiomycota

Blastocladiomycota

Zoopagomycota

Glomeromycota

Mucoromycota

Basidiomycota

Ascomycota

What were the first fungi like

single celled and aquatic producing motile asexual spores (zoospores) similar to chytridiomycota

Characteristics of Chytridiomycota PHYLUM

predominantly aquatic, coenocytic mycelium only in certain genera zoosporic dissemination stage (means motile)

prey on small naive populations then they kill lots of individuals

frog parasite

What does zoosporic mean?

motile with a flagella for movement

Characteristics of Neocallimastigomycota Phylum

only in guts of animals

small group of flagellates obligate anaerobic non parasitic fungi

lack true mitochondria use hydrosomes to make ATP instead

locates only in the guts of mammals that do not produce the enzyme to degrade celllulose\

no known sexual stages

When did the evolution of land dwelling fungi happen?

around 700 mya

What replaces the motile spores in terrestrial fungi

thick walled zygospores

what are the two first land fungi phyla

Zoopagomycota and mucromycota

Characteristics of Mucoromycotina

300+ spp. including common saprobes and plant/animal pathogens

well developed mycelium

aseptate (coenocytic)

No spreading mycelium

Rhizoids/stolons (short thin filaments that act as roots)

What has more variation in a fungi sexual or asexual components?

Zygospores (asexual) vary in minor ways between species

anamorphs (sexual stage) have adapted in amazing and bizarre ways

Why do anamorphs or sexual stages vary more than asexual stages

• The function of the teleomorph is due to the long-term survival without sexual reproduction in stressful conditions you would die and end the lineage of mushrooms, so they have structures with minimal surface area and thick protective walls.

• the function of anamorphs (asexual) is to disperse their spores adn is achieves in many ways

What fungi can shoot its spore up to 2m

Pilobolus sphaerosporus

What’s alexander weirs favorite fungi

Kickxellomycotina DNA like structures curl around mycelia

Glomeromycota characteristics

200 spp.

found withing roots of a vast majority of plants 75% of plants

spore ball within roots of plants (produces large vesicles)

penetrate cells to for intricately connected arbuscules

Characteristics of Laboulbeniales

wide range of insect hosts

easily seen on integument

large collections available

monophyletic

Who is Rowan Thaxter

the very first scientist to study laboulbeniales ( insect parasitic fungi)

What is the name of the sexually transmitted disease on ladybugs

Hesperomyces virescens

What natural phenomenon were fungi associated with in early years

thunder and lightning myan hindu greek

When was the first time we saw fungal spores and finally could decipher what mushrooms were

1588

Who is Lazzaro Spallanzani

He worked with Rhizopus and showed that fungal spores could withstand higher temps than seeds, also growth is influenced by temp and humidity

Why did linneas classify fungi as worms

he only knew things that developed from seed and the genetalia, so spores with no obvious genetalia confused him

What is fungi pleomorphism

where one singular fungi can have different types of spores in the same lifecycle

What did the Tulsane brothers add to the growing knowledge of fungi in 1851-1865

various kinds of seeds and fruits are produced either simultaneously or in succession by the same fungus

What did persune do to advance scientific knowledge

introduced the concept of the hymenium adn described species

What did fries contribute to mycology

at age 17 he could distinguish 300-400 spp of fungi.

described nearly 5000 species of fungi with a large emphasis on spore color

Reverand Burkley

remembered for his work on fungal diseases on plants potatoes and wheat rust and grape mildew

named 6000 species

Agostino Bassi

saved the silk trade by first discovering a fungal parasite using a microscope

Pier Andrea Saccardo

one of the most prolific taxonomist of fungi

proposed a color scale for naming plant pigments

new system of classifying fungi by spore color and form

flaviconia the yellow

how do fungi digest and what do they digest

the spew out digestive enzymes then eat the cellulose and lignin and other things

What about a fungi determines where it grows

the chemicals in their digestion enzyme slurry (what it can eat)

some only live in the stomach of mammals

What are fungi made out of and what do they store in their cells for energy

call walls of chitin and composed of hyphae they store glycogen instead of starch.

What is the structure at the end of a hyphae called

spitzenkorper

What fungi are aseptate what fungi are septate

basidios and ascos are septate but functionally coenocytic and zygomycetes are aseptate

In complex Basidiomycota how are the cells divided and what are these structures called

they have dolipore septa and parenthasomes

What is the optimal pH for growing mushrooms

4-7

How much light do fungi need to live

the don’t actually need light to reproduce

What life strategy do fungi preform

usually saprobic, decompose dead material

parasitic— eat host

mutalistic— mycorrhizal assicated btwn roots adn fungus

What is the fusion of nuclei called

karyogamy

How do fungi protect themselves from harsh environmental conditions

they can produce a resting spore

How do basidiomycete lifecycles differ in the dilaryotic stage compared to ascomycetes

ascomycetes have a short lived dikaryotic n+n stage but basicdios have a very long one

Why are basidiomycetes important

they contain mostly parasites of plant causing agricultural failure

destruction of wood products

principle agents of decay of cellulose and lignin

important food source

mycorrhizal species in natural managed forests

what are most ascomycete fungi?

peziziomycetes

What fungi have no hyphae and spreading mycelia

mucromycotina

What type of fungi are Agaricomycotina?

mushrooms, puffballs, shelf fungi, jelly fungi

What are rhizomorphs

hyphae lying parallel to each other forming thick “roots” sometimes enveloped in a sheath

What are the three stages of basidiomycete mycelium

primary, n results from germination of basidiospore

secondary, n+n long lived results from plasmogamy characterized by clamp connections

tertiary mycelium, n represented by the tissues that make up the basidiocarp

How do basidiomycetes maintain the dikaryotic stage

clamp connections

What kind of structures do basidiomycetes have in place to maintain septate hyphae

dolipore septa, septal pore caps, parenthasomes

What are cystidia

larger hymenial element variety of shapes taxonomically important howoever we do not know what their use is

Explain how the basidium develops

karyogamy, meiosis 1, meiosis 2, migration of haploid nuclei into basidiospores

What is the difference between fungi sexual compatibility and sex

on the basis of sex they fall into three categories based off of what female and male organs they share the compatibility is if they can self fertilize or need another mycelium to pollinate themselves

What does hermaphroditic mean in fungi

every thallus bears both male and female organs,, they do not have to be compatible

What does it mean to be sexually dioecious

some thalli bear only male and some thalli bear only female organs ( very few dioecious fungi have been found)

What does it mean to be sexually undifferentiated

sexual organs are morphologically indistinguishable as male/female

What does homothallic mean

every thallus is self fertile (excludes dioecious) they have no mating types and are non outcrossing

what does heterothallic mean

every thallus is sexually self sterile, these fungi are outcrossing

What is the class of mushrooms that contain 700% of all basidios

Agaricomycetes

What is the jelly fungus class that causes brown rot

dacrymycetes

What is the scientific name for LSD

Claviceps purpurea

What is the most deadly genus of fungi

Amanita

What are teh two types of toxins in amanita mushrooms

amatoxins, phallotoxins

Common test to determine if amatoxins are present in mushrooms

Meixner test squash mushrooms watch for blue color change high concentrations only 1-2 minutes

What is the method of diagnosing amanita poisoning in France

The Bastien treatment (take vitamins and control fluid and electrolyte balance)

How to remove mushroom toxins from your system?

using charcoal, haemodialysis, increase rate of excretion, maintain proper blood sugar level adn electrolyte and fluid balancewhat are teh effects of amatoxins

what are the effects of amatoxins

attack cell nucleus and bind to RNA polymerase 2

so there not rna—> no protein—> cell dies