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 Mycology- study of fungus 2

Characteristics 3

 Fungi are NOT plants (they are eukaryotes)  Non-photosynthetic (chemoheterotrophs- require organic compounds for energy) 4

 Most are aerobic  Non-motile  Most are saprobes (live on dead organisms)  Release digestive enzymes to break down organic material or their host 5 BREAD MOLD

 Important decomposers & recyclers of nutrients in the environment  Most are multicellular, except unicellular yeast  Lack true roots, stems or leaves MULTICELLULAR MUSHROOM UNICELLULAR YEAST 6

 Some fungi are internal or external parasites  A few fungi act like predators & capture prey like roundworms Predaceous Fungi feeding on a Nematode (roundworm) 7

 Some are edible, while others are poisonous EDIBLE POISONOUS 8

 Produce both sexual and asexual spores  Classified by their sexual reproductive structures Spores come in various shapes 9

 Fungi include puffballs, yeasts, mushrooms, toadstools, rusts, smuts, ringworm, and molds  The antibiotic penicillin is made by the Penicillium mold Penicillium mold Puffball 10

Vegetative Structures 11

 Cell walls are made of chitin (complex polysaccharide)  Body is called the Thallus  Grow as microscopic tubes or filaments called hyphae 12

 Tubular  Tubular shape  ONE  ONE continuous cell cytoplasm & nuclei  Filled with cytoplasm & nuclei  Multinucleate chitin  Hard cell wall of chitin also in insect exoskeletons 13

 Stolons  Stolons – horizontal hyphae that connect groups of hyphae to each other  Rhizoids  Rhizoids – rootlike parts of hyphae that anchor the fungus 14 STOLON RHIZOIDS

 Cross-walls called SEPTA may form compartments  Septa have pores for movement of cytoplasm  Form network called mycelia that run through the thallus (body) 15

 Fungi get carbon from organic sources  Tips of Hyphae release enzymes  Enzymatic breakdown of substrate  Products diffuse back into hyphae Digested material is then used by the hypha Nucleus “directs” the digestive process

 Fungi may be classified based on cell division (with or without cytokinesis)  Aseptate or coenocytic (without septa)  Septate (with septa) 17 NO CROSS WALLS CROSS WALLS

18 HAUSTORIA – parasitic hyphae on plants & animals Septate Hyphae Coenocytic Hyphae

 Hyphae grow from their tips  Mycelium is an extensive, feeding web of hyphae  Mycelia are the ecologically active bodies of fungi This wall is rigidOnly the tip wall is plastic and stretches 19

REPRODUCTIVE STRUCTURES 20

Asexually Sexually  Most fungi reproduce Asexually and Sexually by spores most common genetically identical  ASEXUAL reproduction is most common method & produces genetically identical organisms conditions are poor & nutrients scarce  Fungi reproduce SEXUALLY when conditions are poor & nutrients scarce 21

adaptation  Spores are an adaptation to life on land species will disperse to new locations  Ensure that the species will disperse to new locations reproductive cell  Each spore contains a reproductive cell that forms a new organism  Nonmotile wind  Dispersed by wind 22

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 Used when environmental conditions are poor (lack of nutrients, space, moisture…)  No male or female fungi  Some fungi show dimorphism  May grow as MYCELIA or a YEAST –LIKE state (Filament at 25 o C & Round at 37 o C) 24 Dimorphic Fungi

1n hyphae 2 mating types (+ and -) FUSE (Fertilization)  Haploid 1n hyphae from 2 mating types (+ and -) FUSE (Fertilization)  Forms a hyphae with 2 nuclei that becomes a ZYGOTE  The zygote divides to make a SPORE SPORE FORMS

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 Fragmentation  Fragmentation – part of the mycelium becomes separated & begins a life of its own  Budding  Budding – a small cell forms & gets pinched off as it grows to full size  Used by yeasts  Asexual spores – production of spores by a single mycelium 27

 Spores may be Formed:  Directly on hyphae  Inside sporangia  On Fruiting bodies Amanita fruiting body Pilobolus sporangia Penicillium hyphae

 Fruiting Bodies asexual  Fruiting Bodies are modified hyphae that make asexual spores Sporangiosphore Sporangium  An upright stalk called the Sporangiosphore supports the spore case or Sporangium 29

 Types of Fruiting Bodies:  Basidia  Sporangia  Ascus 30 Basidia Sporangia

mycelium Fruiting Bodies Both are composed of hyphae 31

 Mycelia have a huge surface area  More surface area aids digestion & absorption of food mycelium Germinating spore 32

REPRODUCTIVE STRUCTURES and SPORES  Fungi are classified by their REPRODUCTIVE STRUCTURES and SPORES  The reproductive structures are: BASIDIA - BASIDIOMYCOTA  BASIDIA - BASIDIOMYCOTA  SPORANGIA - ZYGOSPORANGIA  ASCUS - ASCOMYCOTA 33

 Spores are made of:  Dehydrated cytoplasm  Protective coat  Haploid cell  Wind, animals, water, & insects spread spores  Spores germinates when they land on a moist surface (new hyphae form) 34

 Saprobes  Decomposers  Molds, mushrooms, etc.  Parasites  Harm host  Rusts and smuts (attack plants)  Mutualists  Both benefit  Lichens  Mycorrhizas 35

 Basidiomycota –  Basidiomycota – Club Fungi  Zygomycota –  Zygomycota – Bread Molds  Chytridiomycota –  Chytridiomycota – Chytrids  AM Fungi -  AM Fungi - Mycorrhizas  Ascomycota –  Ascomycota – Sac Fungi  Lichens –  Lichens – Symbiosis (algae & Fungi)

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 Called the sporangium fungi  Commonly called molds  Also includes blights  Hyphae have no cross walls (aseptate)  Grow rapidly  Includes bread mold Rhizopus stolonifer Rhizopus on strawberries Tomato Blight

sporangiumsporangiospores spores  Asexual reproductive structure called sporangium atop sporangiospores make spores  Rhizoids  Rhizoids anchor the mold & release digestive enzymes & absorb food  Stolons  Stolons connect the fruiting bodies

 Sexual conjugation hyphae fuse  Sexual spores are produced by conjugation when (+) hyphae and (-) hyphae fuse ZYGOSPORES  Sexual spores are called ZYGOSPORES endure harsh environments  Zygospores can endure harsh environments until conditions improve zygospore

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 Called Club fungi  Includes:  Mushrooms  Toadstools  Bracket & Shelf fungi  Puffballs  Stinkhorns  Rusts and smuts

(mushrooms)  Some are used as food (mushrooms) (rusts & smuts)  Others damage crops (rusts & smuts) Corn Smut Soybean Rust Portobello Mushrooms

 Seldom  Seldom reproduce asexually fruiting body  The visible mushroom is a fruiting body  Basidiocarp stipe cap Basidia  Basidiocarp (fruiting body) is made of a stalk called the stipe and a flattened cap with gills called Basidia underneath  Basidiospores  Basidiospores are found on basidia  Annulus  Annulus is a skirt-like ring around some stipes  Vegetative  Vegetative structures found below ground 44

Fig Nuclear fusion in basidium Meiosis Hyphal fusion of haploid mycelia haploid mycelium young basidia - the only diploid cells mycelium and fruiting body are dikaryotic N 2N N+N 45

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Sac fungi  Called Sac fungi Cup fungi, morels, truffles, yeasts, mildew  Includes Cup fungi, morels, truffles, yeasts, and mildew (Dutch elm disease and Chestnut blight)  May be plant parasites (Dutch elm disease and Chestnut blight)  Reproduce sexually & asexually  Ascus ascospores  Ascus - sac that makes ascospores in sexual reproduction Ascocarps  Specialized hyphae known as Ascocarps contain the asci

budding  Yeasts reproduce asexually by budding (buds break off to make more yeast cells)  Asexual conidia conidiophores  Asexual spores called conidia form on the tips of special hyphae called conidiophores CONIDIA

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Saccharomyces

 Trufflesmorels  Truffles and morels are good examples of edible ascomycetes  Penicillium mold  Penicillium mold makes the antibiotic penicillin. flavor to cheeses.  Some ascomycetes also gives flavor to certain cheeses.  Saccharomyces cerevesiae  Saccharomyces cerevesiae (yeast) is used to make bread rise and to ferment beer & wine.

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chytrids  Called chytrids motile spores  Produce motile spores saprobes parasites  Mostly saprobes and parasites in aquatic habitats  Biodegrade and recycle  Biodegrade and recycle nutrient s Chytrid that attacks Potatoes

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associated with plant roots  Fungus associated with plant roots  Mutualism  Mutualism between :  Fungus  Fungus (nutrient & water uptake for plant)  Plant  Plant (carbohydrate for fungus) kinds  Several kinds :  Zygomycota – hyphae invade root cells  Ascomycota & Basidiomycota – hyphae invade root but don’t penetrate cells  Extremely important ecologically 55