Lecture 15 MYCORRHIZAS http://www.mykoweb.com http://www.ffp.csiro.au/research/mycorrhiza/intro.html http://www.fs.fed.us/pnw/mycology/photo/index.html

The belowground ecosystem

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

Mycorrhizas and Plant Succession

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

Molina

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

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

Mycorrhizas are old – been around 460 million years

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

Fungal Phyla Basidiomycota – mushrooms, puffballs,etc Ascomycota – truffles Glomeromycota Thousands of species of ectomycorrhizal fungi (Basidiomycota and Ascomycota– few plant species) - 2000 species of fungi are mycorrhizal with Douglas-fir Few species of arbuscular fungi (AM) (Glomeromycota) – most plant species

-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

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-

Ectomycorrhizal Fungi Basidiomycota Suillus sp.

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

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

Ectomycorrhizal root Morphotypes

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

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

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

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

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

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

Douglas-fir ectendomycorrhizae – Randy Molina, USFS

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

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

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.

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

Phytophthora treatment in Washington Park Arboretum

Ectomycorrhizal pine roots Non-ectomycorrhizal pine roots

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?