Download presentation
Presentation is loading. Please wait.
Published byMelvyn McDaniel Modified over 8 years ago
1
1
2
Mycology- study of fungus 2
3
Characteristics 3
4
Fungi are NOT plants (they are eukaryotes) Non-photosynthetic (chemoheterotrophs- require organic compounds for energy) 4
5
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
6
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
7
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
8
Some are edible, while others are poisonous EDIBLE POISONOUS 8
9
Produce both sexual and asexual spores Classified by their sexual reproductive structures Spores come in various shapes 9
10
Fungi include puffballs, yeasts, mushrooms, toadstools, rusts, smuts, ringworm, and molds The antibiotic penicillin is made by the Penicillium mold Penicillium mold Puffball 10
11
Vegetative Structures 11
12
Cell walls are made of chitin (complex polysaccharide) Body is called the Thallus Grow as microscopic tubes or filaments called hyphae 12
13
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
14
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
15
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
16
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
17
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
18 HAUSTORIA – parasitic hyphae on plants & animals Septate Hyphae Coenocytic Hyphae
19
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
20
REPRODUCTIVE STRUCTURES 20
21
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
22
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
23
23
24
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
25
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 25 + - SPORE FORMS
26
26
27
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
28
Spores may be Formed: Directly on hyphae Inside sporangia On Fruiting bodies Amanita fruiting body Pilobolus sporangia Penicillium hyphae
29
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
30
Types of Fruiting Bodies: Basidia Sporangia Ascus 30 Basidia Sporangia
31
mycelium Fruiting Bodies Both are composed of hyphae 31
32
Mycelia have a huge surface area More surface area aids digestion & absorption of food mycelium Germinating spore 32
33
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
34
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
35
Saprobes Decomposers Molds, mushrooms, etc. Parasites Harm host Rusts and smuts (attack plants) Mutualists Both benefit Lichens Mycorrhizas 35
36
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)
37
37
38
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
39
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
40
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
41
41
42
Called Club fungi Includes: Mushrooms Toadstools Bracket & Shelf fungi Puffballs Stinkhorns Rusts and smuts
43
(mushrooms) Some are used as food (mushrooms) (rusts & smuts) Others damage crops (rusts & smuts) Corn Smut Soybean Rust Portobello Mushrooms
44
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
45
Fig 31.12 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
46
46
47
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
48
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
49
49
50
Saccharomyces
51
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.
52
52
53
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
54
54
55
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
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.