1. Lecture 15 MYCORRHIZAS http://www.mykoweb.com

2. The belowground ecosystem

4. Mycorrhizal mat in the Olympic rain forest
-yellow fungus is Piloderma

6. Mycorrhizas and Plant Succession

7. Do mycorrhizal fungi change with stand age in
Pacific Northwest Douglas-fir/hemlock forests?
Cantherellus
formosus
Laccaria laccata
Russula xerampelina
Young forests
Mature and old-growth forests
Photos – Canadian Forest Service

8. Molina

9. b. Other benefits to ecosystems c. Value to humans
Lecture Topics
Mycorrhizas
1. What are mycorrhizas
2. Types of mycorrhizas
3. Roles of mycorrhizas
a. Benefits to plants
b. Other benefits to ecosystems
c. Value to humans
d. Protection against pathogens
e. How important are they in urban ecosystems

10. 1. What are mycorrhizas? MYCORRHIZA Greek – Root + Fungus association)
(fine root/fungal mutualistic symbiotic
association)

11. Mycorrhizas are old –
been around 460 million years

12. 2. Types of Mycorrhizas Ectomycorrhizas (ECM)
Endomycorrhizas – Arbuscular (AM) or vesicular arbuscular (VAM)
Ericoid
Ectendomycorrhizas
Arbutoid
Monotropoid
Orchid

13. Fungal Phyla Basidiomycota – mushrooms, puffballs,etc
Ascomycota – truffles
Glomeromycota
Thousands of species of ectomycorrhizal
fungi (Basidiomycota and Ascomycota– few plant species) species of fungi are mycorrhizal with Douglas-fir
Few species of arbuscular fungi (AM) (Glomeromycota) – most plant species

14. -plant provides sugars to fungus
- fungus provides nutrients and water to plants and
protects plants against pathogens
Most plant families are mycorrhizal (90%)
Non mycorrhizal plants – aquatic, mustard family
Types of mycorrhizas and plant families
- Ectomycorrhizae – Pineacea, Betulaceae, Fagaceae
- Endomycorrhizae (arbuscular)– most plant families,
Cupressaceae
- Ericaceous – Ericaceae – Erica to Vaccinium
- Arbutoid – Ericacaea - Arbutus, Arctostaphylos and Pyrola
- Orchid – Orchidaceae
- Monotropoid - Monotropaceae
- Ectendo - Pinaceae

15. Gymnosperms & Angiosperms
Type AM
ECM
Ectendo-
Arbutoid
Mono- tropoid
Ericoid
Orchid
Septate hyphae
- (+)
+ - +
Hyphae in cells -
Hyphal coils
Arbuscules
Mantle
+ (-)
Hartig net
Vesicles
Plants
Vascular plants
Gymnosperms & Angiosperms
Ericales
Mono- tropaceae
Orchid- aceae
Chlorophyll
Fungi
Glomero-mycota
Most Basid-, but some Asco- and Zygo-
Asco- (Basid-)
Basid-

16. Ectomycorrhizal Fungi
Basidiomycota
Suillus sp.

17. Belowground ectomycorrhizal
fungi – spores spread by
small mammals eating fruiting
bodies (truffles - Ascomycota)

18. Cross section of Douglas-fir fine Root showing ectomycorrhizal
Hyphae (with crosswalls –septate)
do not penetrate plant cell walls
Hartig net
Mantle
Two ectomycorrhizal
fungi forming mantle
on same fine root
Cross section of Douglas-fir fine
Root showing ectomycorrhizal
mantle and Hartig net

19. Ectomycorrhizal root Morphotypes

20. Mycorrhizal types at Findley Lake
Microsclerotia (resting stage)
Several different fungi
Can occur on one root
Black one is Cenococcum

21. Arbuscular mycorrhiza (AM) (Vesicular arbuscular mycorrhizas)
ENDOMYCORRHIZAS
Arbuscular mycorrhiza (AM)
(Vesicular arbuscular mycorrhizas)
No mantle, no Hartig net
Arbuscules
Hyphae (without crosswalls) penetrate cell wall, but not cell membrane
Large spores
Glomus
Vesicles

22. ARBUTOID MYCORRHIZA
Arbutus
Hyphae in cells
Hartig net
Mantle
No Hyphal coils

23. Achlorophyllous plants are connected to trees via mycorrhizal fungi
Monotropoid
Hyphae in cells
Hartig net
Mantle
No Hyphal coils

24. ERICOID MYCORRHIZA
Hyphae in cells
Hyphal coils
No Hartig net
No mantle

25. ORCHID MYCORRHIZA
Rhizoctonia, Armillaria
Hyphae in cells
Hyphal coils
No Hartig net
No mantle

26. Douglas-fir ectendomycorrhizae – Randy Molina, USFS

27. Protection from parasitic fungi and nematodes
2. ROLES OF MYCORRHIZAS
a. Benefits to plants
Increase plant nutrient supply by increasing root surface and acquiring nutrient forms (organic) normally available.
Protection from parasitic fungi and nematodes
Improving water relations and phytohormones

28. b. Other benefits to ecosystems
Soil hyphae may prevent nutrient losses from the system, especially at times when roots are inactive.
Hyphae are conduits that may transport carbon and nutrients from one plant species to another through mycorrhizal hyphal network. Argument
for biodiversity
Provide food for mammals and invertebrates

29. Fungal diversity is a bio-indicator of environmental quality.
c. Values to people
ECM fungi are economically and nutritionally important as human food resources. These mushrooms have also have been used as medicines and natural dyes. Fungi have aesthetic values and are an important part of the as culture, folklore and appreciation of nature by many people
Fungal diversity is a bio-indicator of environmental quality.
Fungi which have adapted to local soil conditions are required for agriculture, horticulture and forestry.

30. d. Protection against plant pathogens
Phytophthora symptoms on Port Orford Cedar

31. Phytophthora treatment in Washington Park Arboretum

32. Ectomycorrhizal
pine roots
Non-ectomycorrhizal
pine roots

33. e. How important are mycorrhizas in urban ecosystems?
What is the mycorrhizal status of urban plants?
Do we need to inoculate urban soils/plants?
How important are they in urban ecosystem restoration?
Do invasive species influence mycorrhizas?