Lecture 5a: Fungal diversity

Question 1

which fungal species are easier to discover

Answer 1

Species that produce spore-bearing structures, because they are visible

Question 2

What do taxonomists do

Answer 2

They have the task to uncover and name new fungal species

Question 3

What is the basis for describing fungi

Answer 3

Morphological, anatomical and chemical characteristics

Question 4

What is the importance of molecular technology-based fungal studies?

Answer 4

They provide a better understanding of fungal diversity and DNA-based data

Question 5

What do Fungal DNA-based studies use

Answer 5

Internal Transcribed Spacer Region (ITS)

Question 6

What is ITS

Answer 6

It is a nuclear ribosomal repeat unit composed of 3 parts, flanked by the SSU and LSU

Question 7

What can ITS do?

Answer 7

they can identify fungi at a species level (fungal barcode)

Question 8

What is the secondary barcode?

Answer 8

Translation elongation factor 1 (tef1)

Question 9

What is the largest group of fungi?

Answer 9

Ascomycota

Question 10

What is the sexual state of Ascomycota characterised by

Answer 10

Ascocarp (fruiting body) containing asci that produce ascospores (1n)

Question 11

How does asexual reproduction occur in Ascomycota?

Answer 11

it takes place through conidia

Question 12

When is the dikaryophase produced?

Answer 12

Shortly before ascus production through the formation of crozier

Question 13

What is a crozier?

Answer 13

An anatomical feature that forms at the base of the ascus, it maintains the dikaryotic state in the ascus

Question 14

How are croziers formed?

Answer 14

See slides, too long to type

Question 15

Types of ascocarps and their scientific names

Answer 15

• Naked ascus- Neolecta spp.
• Cleisothecium- Uncinula spp.
• Pseudothecium- Venturia
• Perithecium- Sordaria
• Apothecium- peziza

Question 16

Unitunicate-Operculate asci

Answer 16

They are single-celled with built-in lids, and the lip pops open at maturity to eject spores. (found in apothecium)

Question 17

Unitunicate-Inoperculate asci

Answer 17

Have a single cell wall with no lid. They have a special elastic ring mechanism built into their tip
the ring stretches momentarily or turns inside out to shoot spores out (found in perithecium)

Question 18

Bitunicate asci

Answer 18

Have double cell walls (outer-thin, inner- thick & elastic)
At maturity, the thin outer wall splits and the outer wall absorbs water to expand upwards.
allows ascus to stretch into the neck of perithecium to expel spores

Question 19

Protunicate asci

Answer 19

Observes no active spore shooting, rather the wall dissolves at maturity and releases the ascospores which then ooze out of the ascocarp
These are found in Ceistothecium

Question 20

South African Ascomycetes

Answer 20

kalaharituber pfeilbi (‘Kalahari truffel’)

Question 21

What does the class of Basidiomycota consist of

Answer 21

Mushrooms, rusts and smuts

Question 22

What is the sexual state of Basidiomycota characterised by

Answer 22

Its characterised by a basidiocarp containing basidium-producing basidiospores

Question 23

What is the extended dikaryophase maintained by?

Answer 23

It is maintained throughout most of the life cycle of hyphae through clamp connection

Question 24

What do secondary hyphae result from?

Answer 24

Fusion between 2 primary hyphae

Question 25

What happens after plasmogamy?

Answer 25

The dolipore septum breaks down to allow nuclear migration

Question 26

What is a clamp connection?

Answer 26

A structure formed by growing hyphal cells to ensures that each cell or segment of hyphae receives a set of different nuclei obtained through mating

Question 27

What is the significance of clamp connections?

Answer 27

They create genetic variation within the hyphae

Question 28

What is the largest organism in the world?

Answer 28

Mushrooms (honey fungus-Armillaria)
Basidiomycota

Question 29

Are Armillaria mushrooms safe to eat raw

Answer 29

No, they are slightly poisonous if eaten raw