Chapter 19 Botany

Mushroom of phylum basidiomycota

composed of cap = pileus, stalk = stipe, and annulus

heterotrophs

All true fungi are filamentous or unicellular. most of which absorb their food in solution through cell walls

Lichen:Crustose

Attached to or embedded in substrate over entire lower surface

Phylum Zygomycota - The coenocytic true fungi

Black bread molds - Best-known members of this phylum Rhizopus - Well-known and found everywhere Asexual reproduction: Sporangiophores grow upright and produce sporangia at tips. Black spores formed in sporangia

Distingues between protista and fungi

Chitin in cell walls All are filamentous, with the exception of some chytrids and all yeasts. Most lack motile cells. Members of Kingdom Fungi are placed in five phyla.

Lichens

Consist of a fungus and an alga (or cyanobacterium) intimately associated in a spongy thallus Photosynthetic component supplies food. Fungus protects the photosynthetic organism from harmful light intensities, and absorbs and retains water and minerals. Three genera of green algae and one genus of cyanobacterium involved in 90% of all lichen species. Each lichen has own unique species of fungus, usually a sac fungus. Lichen species are identified according to their fungus

Lichen: Foliose

Contain leaf-like thalli which often overlap

Phylum Basidiomycota: Fairy Rings

Dikaryotic hyphae radiate out from starting point, producing basidiomata

monokaryotic hyphae

Each cell of hyphae contain a single haploid nucleus

Phylum Basidiomycota: Bird's nest fungi

Egglike bodies contain basidiospores

Phylum Ascomycota - The ascomycetes (sac fungi) Human and ecological relevance

Ergot fungus may infect rye and other grains. Ergotism may occur in those who eat the contaminated bread. Ergot drugs are medicinally useful in small doses. Initial source for the manufacture of LSD Plant diseases - Dutch elm disease, chestnut blight

Human and ecological relevance of lichens

Exceptionally sensitive to pollution. Sulfur dioxide. Possible to calculate amount of sulfur dioxide present in air solely by mapping occurrence or disappearance of certain lichens. Nuclear radiation. Degradation of historic structures. Food for animals - Reindeer eat fruticose lichen. Food supplements. Antibiotic properties. Dyes.

Kingdom Fungi

Fungi and bacteria are the most important organisms that break down organic materials. Fungi produce intertwined mass of delicate threads.

Phylum Deuteromycota - The deuteromycetes (imperfect fungi)

Fungi for which a sexual stage has not been observed. Grouped together in an artificial phylum. Most commonly reproduce by conidia.

Phylum Basidiomycota: Shelf fungi

Grow horizontally from bark or dead wood

Phylum Basidiomycota - The basidiomycetes (club fungi) Sexual Reproduction

Hyphae of individual mating types unite and initiate a new mycelium, called dikaryotic hyphae, in which each cell has one nucleus from each original mating type. Dikaryotic mycelium forms basidioma (plural: basidiomata) = mushroom. Basidia (swollen ends of hyphae) on gills. The two nuclei in each basidium unite and the resulting diploid nucleus undergoes meiosis.

Phylum Basidiomycota - The basidiomycetes (club fungi)

Includes mushrooms, toadstools, puffballs, shelf fungi, rusts, smuts, jelly fungi Hyphae divided into individual cells.

Hyphae

Individual threads

Phylum Basidiomycota - The basidiomycetes (club fungi) Asexual reproduction

Infrequent Mainly through conidia

Mycelium

Mass of hyphae

Rusts

Parasitic species that do not form basidiomata. Attack a wide variety of plants. Black stem rust - Requires two hosts

Smuts

Parasitic species that do not form basidiomata. Grain crops. Mycelium absorbs nutrients from host cells. Secrete substances that stimulate host cells to form tumors

Phylum Deuteromycota - The deuteromycetes (imperfect fungi) Human and ecological relevance of the imperfect fungi

Penicillium Antibiotics Gourmet cheese Aspergillus Citric acid, soy sauce, miso, artificial flavoring Photographic developers, dyes Aspergilloses (respiratory disease), athlete's foot Aflotoxin (carcinogen

Gills

Plates that radiate out from stalk on underside of cap

Phylum Basidiomycota Human and ecological relevance of the club fungi

Poisonous. Fewer than 75 of the approximately 25,000 described species are poisonous. Food: Shiitake mushrooms High in protein, calcium, phosphorous, and iron. Portabella mushrooms. Lentinacin and other pharmaceutical extracts. Nutrient recycling in soil.

Phylum Basidiomycota: Boletes

Produce spores on surface of pores instead of gills

Lichen:Fruticose

Resemble miniature upright shrubs, or hang down in festoons from branches

Phylum Chytridiomycota - The chytrids

Simple, mostly one-celled organisms Some are parasitic, and other are saprobic. Saprobic - Feed on nonliving organic material Some consist of a spherical cell with colorless, branching threads (rhizoids) at one end for anchorage.

Phylum Basidiomycota: Puffballs

Spores released from pore at top

Phylum Ascomycota - The ascomycetes (sac fungi)

Truffles are reproductive bodies. Also includes yeasts, powdery mildews, ergot, and morels. Human and ecological relevance of the sac fungi: Food: Morels and truffles. Yeast. Fermentation produces ethyl alcohol - Wines, beers. CO2 causes bread dough to rise and gives it porous texture.