Ectomycorrhizaepdf

Ectomycorrhizae
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Pratylenchus penetrans
Peterson, R.L., et. al. 2006

Abiotic Disorders & ECM
Nutrient deficiency symptoms less likely on ECM plants
Ectomycorrhizae
Most ECM fungi are Basidiomycota
(e.g. Amanita, Amanita, Boletus, Cantharellus, Cortinarius, Entoloma, Entoloma, Gomphidius, Hebeloma, Hygrophorus, Inocybe, Lactarius, Paxillus, Rhizopogon, Russula, Scleroderma, Scleroderma, Suillus, Thelephora, Tomentella)
Ectomycorrhizae
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Peterson, R.L., et. al. 2006
Ectomycorrhizae
Root hair
Hypha of Cenococcum geophyllum
>2000 hyphae may emanate from one mycorrhiza 4 m of hyphae in 1 mL of soil
Peterson, R.L., et. al. 2006 , Kwantlen.ca/Horticulture
Some ECM fungi are Ascomycota (e.g. Cenococcum, Muciturbo, Sphaerosporella, and, as shown, Tuber)
Leaf scorch symptoms less likely as many ECM fungi can grow at water potentials well below the permanent wilting point of the plant
Toxic metals (Fe, Al, Mn, S) or excessive nutrients are more likely filtered out on ECM plants
Arbuscular mycorrhizae
Ectomycorrhizae
Endomycorrhizae
Ericoid mycorrhizae
Orchid mycorrhizae
Ectendomycorrhizae
/mycorrhizae/ectomycorrhizae.html
• Some of these antibiotics are antifungal on Rhizoctonia solani, Pythium debaryanum and Fusarium oxyporum
• The mantle may exclude nematodes
/mycorrhizae/resistance-to-plant-diseases-by-ectomycorrhiza.html
Trappe and Vogel, 1977
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Hyphae may combine to from mycelial strands or rhizomorphs
May grow several meters and transport water and nutrients (especially Nitrogen, Phosphorus, Potassium) to the roots
• Mantle (m): fungal sheath on the root surface like a glove
• Hartig net (n): hyphae between root epidermal and cortical cells (c)
Mantle Hartig net Primary phloem Primary xylem Endodermis Cortical cell
Hypha
(non-mycorrhizal “textbook” root c.s.)
Ectomycorrhizae
are morphologically distinctive
Ectomycorrhizae
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ECM may protect against root pathogens
• Species of certain ECM fungi (e.g. Lactarius, Cortinarius, and Hygrophorus) produce antibiotic substances
• Hyphae emanating from the mantle may extend several centimeters in to the surrounding soil
• Hyphae are small diameter and long and therefore have a much greater surface area than do roots or root hairs
Smith, S.E. and. D.J. Read. 1997
Ectomycorrhizae
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Photo Credits (images with no URL shown)
Peterson, R.L., et. al. 2006. Mycorrhizas: Anatomy and Cell Biology Images. NRC Research Press.
Ectomycorrhizae (ECM)
• “Ecto-” means outside and in the case of ECM it means the fungal hyphae do not normally penetrate into healthy cortical cells of the plant
Roth, A.L. 1990. Mycorrhizae of Outplanted Conifers. M.Sc. Thesis. University of British Columbia. 298 p
Roth, A.L. Kwantlen Plant Database (www.Kwantlen.ca/Hort)
Ectomycorrhizae
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Selected References
Smith, S.E. and. D.J. Read. 1997. Mycorrhizal Symbiosis (2nd Ed.). 605 pp. Academic Press, San Diego and London
Ectomycorrhizae
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Whipps, J.M. 2000. Microbial Interactions in the Rhizosphere. J. Exp. Botany. V. 52: 487-511
Zhang, R.Q. et. al. 2010. Forest Pathology (on-line) 28 JUL 2010
• Hyphae access soil micropore space to reach more water and nutrients in dry conditions
• Hyphae may also maintain hydraulic conductivity with the soil as it dries and shrinks
Peterson, R.L., et. al. 2006
And a few ECM fungi are Zygomycota (in the genus Endogone and Glomus)
Ectomycorrhizae
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ECM predominantly occur on the roots of tree species in the Pinaceae (ECM only), Fagaceae, Betulaceae, Salicaceae (may also form AM, a type of endomycorrhizae).