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• Morphology • Reproduction • Ecology • Dissemination SEM of an unidentified fungus on the surface of a seed from Setaria faberii, a large grass, commonly called Giant Foxtail --www.itg.uiuc.edu/ exhibits/iotw/2002-08-29/ • Eukaryotes • Non-Vascular • Reproduce by Spores • Heterotrophs – Can’t Make Their Own Food – Digest then Ingest • Lack of Chlorophyll Profoundly Affects Lifestyle – Both Sexual & Asexual Spores – Alternation of Generations • Vegetative Body Microscopic Threads Called Hyphae • Cell Walls Similar in Structure to Plants – Differ in Chemical Composition • Organelles & their Structures Differ from Plants • More closely Related to Animals than Plants – – – – Not Dependent on Light Can Occupy Dark Habitats Can Grow in any Direction Can Invade the Interior of Substrate with Absorptive Filaments midamericalandrestore.com • Mycelium – Filamentous Body with Many Cells • Hypha – Individual Branches of Mycelium • Size Varies, Growth at Hyphae Tips • Haustoria – Feeding Organs • Sclerotium – Hard Masses of Mycelium http://www.earthfoot.org/backyard/fungi.html; http://www.ent.iastate.edu/imagegal/plantpath/barley/1785.15ergotinbarley.html midamericalandrestore.com Nutritional Status • Saprophytes – Recyclers in Nature • Symbionts (Mutualists) – Mycorrhizae – Lichens • Parasites answers.com 1 • Sporangium Reproduction – Sac or Container that Holds Spores • Chlamydospore • Mainly by Spores – Analogous to the Seed of Green Plants • Successful Organisms • Enormous Numbers of Spores • Many Produce Asexual & Sexual Spores – Sexual or Perfect State Referred to as Teleomorph – Asexual or Imperfect Termed the Anamorph • Spores can Remain Dormant Long Time http://www.wsl.ch/staff/beat.frey/rem_e.html – Thick-Walled Spore Formed from Hypha Cell • Resting Structure for Long-Term Survival • Zoospores: Spores with Flagella that Swim • Most Fungi Can Reproduce Sexually – Mating Types 1. Gametes (Cells) Unite • Produce Zygote – Zygospore, Ascospore, Basidiospore, Oospore 2. Gametes Fuse 3. Mycelium Unite Where Do Fungi Live? Identification • Some on Plant Entire Lives except Spore Stage • Spores & SporeBearing Structures • Sometimes Mycelium Rust spores parasitized by the mycelium of the hyperparasite that grows appressed to the rust spores, coiling around them & forming numerous appressoria. Apsnet.org Monilia fructigena Pers. - Brown Fruit Rot, agroatlas.ru • Soil Fungal Pathogens • Some Part of Lives on Plants & Part on Dead Tissues of Same Host on Ground http://www.scientificamerican.com/gallery_directory.cfm?photo_id=AAE0EFB0-EF07-327E-2BB7A037CC0DDD55 Which Part of the Plant? – On Plants – On Dead Tissues of Host – As Saprophytes on Decaying OM – Wide Host Range – Can Survive in Soil many Years – Need Host occasionally to Increase Populations • Plant Surface with Haustoria • Intercellularly with Haustoria • Xylem Vessels [(a) Courtesy APS; (b) Courtesy Plant Pathology Department, Washington State University] www.microbeorganics.com/ apsnetorg 2 What Kind of Plant Material What Kind of Environment Do They Require? Do They Require? • Obligate Fungi Need Living Cells • Usually Presence of Water • Some Nonobligate Fungi never Contact Living Plant Cells • Zoospores Require Free Water • Spores Broader Ranges of Temp & Moisture – Production, Movement & Germination www.plantcell.org/content/vol17/issue7/cover.dtl • • • • Impacts of Fungi • • • • Many Harmful to Humans & Animals Plant Diseases Rot & Contamination of Foods Can Destroy almost every Kind of Manufactured Good Many Useful to Humans Yeasts for Baking & Brewing Antibiotics & other Drugs Organic Acids Commercially Produced with Fungi – Citric Acid – Steroids & Hormones – Certain ‘Stinky’ Cheeses bio.miami.edu www.eurobloodsubstitutes.com/euroProject.htm info.asapsupplier.com How Do Fungi Spread? In What Form Do They Spread? • Zoospores can Move Short Distances • Usually as Spores • Hyphae Fragments & Sclerotia by Wind, Water, etc. • Most Fungi Rely on Chance Distribution – Wind, Water, Birds, Insects, Animals, Humans omafra.gov.on.ca www.microbeorganics.com/ 3 Active or Passive Spread? Fungi Classes • Major Classes Based on Method of Producing Sexual Spores • Almost always Passive • Distance Carried Depends on Wind, Water, Insect Movement • Some Forcibly Discharge Spores Puffing from Apothecia of Monilinia fructicola (brown rot of stone fruits). apsnet.org 1. Ascomycetes • Sac or Cup Fungi, Spores Borne Internally in a Sac called Ascus • 75% of all Fungi – Most Fungi that Join with Algae to Form Lichens, Baker’s Yeast, Penicillium chrysogenum www.fungi.com/gifts/lockwood.html • Sexual Spores Ascospores – Called Teleomorph or Perfect Stage • Sexual Fruiting Bodies Saclike – Cleistothecium – Perithecium – Pseudothecium – Apothecium • Have Sexual & Asexual Stages – Conidia Are Asexual Spores • Called Anamorph or Imperfect Stage apsnet.org, Courtesy R. Wick • Sexual Stage Seldom Found in Nature • Mostly Found as Mycelium, Conidia or Both • If Water Present, Can Consume Almost Any Carbon Substrate – Jet Fuel, Wall Paint – Biggest Role in Recycling Dead Plant Material • Symbiotic Association with Algae or Plants • Symbioses with Arthropods – Can Line Beetle Galleries – Beetles Maintain Pure Culture of the Fungus Examples of Ascomycetes • Aspergillus flavus – Producer of Aflatoxin Fungal Both a Toxin & Most Potent Known Natural Carcinogen • Cryphonectria parasitica – Chestnut Blight • Ophiostoma ulmi • Candida albicans http://www.ipm.iastate.edu/ipm/icm/node/194 4 • Taphrina, Peach Leaf Curl • Anthracnose Fungi • Venturia inaequalis, • Powdery Mildew Fungi Apple Scab • Sooty Molds • Fusarium • Black Spot of Roses • Verticillium • Botrytis • Claviceps, Ergot of Rye 2. Basiomycetes • Spores Borne Externally on Club-Shaped Structure Called Basidium • Club & Mushroom Fungi • Usually Fleshy • Saprophytes, Wood Decay or Pathogenic including Root & Stem Rots • Most Evolutionary Advanced Fungi • Usually no Asexual Spores botamynus.de • Ectomycorrhizae 3. Zygomycetes • Others Form Symbiotic Associations with • Sexual Spores Thick-Walled Resting Zygospores Insects • Shiitake • Mostly Live in Soil or on Decaying Material • Certain Hallucinogen Toxins • Asexual Zygospores Borne on Stalks • Smuts • ‘Sugar Molds’ • Rusts • Rhizopus ‘Bread Molds’ & Soft Rots • Snow Mold of Turfgrasses • Endomycorrhizae • Heart Rot of Trees clarku.edu Fungal Disease Control 4. Oomycetes • • • • • • • Formerly Classified as Fungi Cellulose Cell Wall Water Molds aka Aquatic Fungi Filamentous Absorb Food from Surrounding Water or Soil Most Saprophytes Some Cause Severe Diseases – Late Blight of Potato – Downy Mildew – Sudden Oak Death Syndrome • • • • • • • • Resistant Plants Destroy Infected Debris Destroy Volunteer Plants or Alternate Hosts Rotate Crops Chemical Sprays or Dusts Sterilize Soil Systemic Fungicides or Hot Water for Seeds Control Insect Vectors protist.i.hosei.ac.jp 5