Publiciastateedubkgelder fungus root mycorrhizae mike

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Unformatted text preview: Root system – Density • Regions rich in moisture and mineral nutrients have greatest root growth • Root length density = cm of roots / cm3 of soil – RLD of 1-2 cm/cm3 is adequate • Density highest near surface, decreases with depth – Species and environment dependent* this basically tells you the depth of the root Mineral Nutrition http://www.public.iastate.edu/~bkgelder/ “fungus” “root Mycorrhizae Mike O’Ryza • From the Greek words for “fungus” and “root” • Symbiotic relationship between plant and fungus – Greatly increases absorbing surface area of root system – Plant gets more water, nutrients – Fungus gets carbohydrate its functions: • Increase absorption of phosphorus, zinc and copper – Can increase rate of uptake and transport by more than 4X – Plant cannot take up ionic phosphorus when soil is basic, mycorrhizae can… they really effiecent in getting phosphorus Mineral Nutrition Mycorrhizae • Two main types “outside” – Ectomycorrhizae Tomas • Form thick sheath of fungal mycelium around roots with some penetrating between cortical cells Epidermis Cortex Mantle (fungal sheath) 100 m Endodermis Fungal hyphae between cortical cells Mantle (fungal sheath) growing outside of the cell wall and Cell Mineral Nutrition (colorized SEM) Mycorrhizae • Two main types “inside” – Endomycorrhizae • Vesicular-arbuscular mycorrhizae (VAM) • Grow between cells and penetrate individual cell WALLS of the root cortex NOT PLASMA MEMBRANES: WHY? they grow into the cell wall and to some degree into the cell, but they dont grow through the plasma membrane. it is “endo” means that it is inside the cell wall but does not penetrate into the plasma membrane of the cell. Epidermis Cortex Cortical cells 10 m Endodermis Fungal hyphae Vesicle Casparian strip Root hair Arbuscules (LM, stained specimen) Mineral Nutrition Mycorrhizae http://www.nature.com/nature/journal/v388/n6642/pdf/388579a0.pdf • What plants? – Endomycorrhizae most common • Arbuscular – common (85% of plant families and most crops) • Ericoid (Ericales) – Ectomycorrhizae more strict to where it is found • Some woody plant families (10% of plant families) • Eucalyptus, oak, pine, rose • basdiomycetes (orchids) – Plants that don’t have mycorrhizae (specialized plants…?): http://mycorrhizas.info/nmplants.html Mineral Nutrition Inga Alley Cropping these are plants that have much interesting adaptation. http://www.ingafoundation.org/alley-cropping/#.UnlZDvnEM9Y Mineral Nutrition...
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This document was uploaded on 01/17/2014.

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