Introduction to Mycology General Mycology Lecture 1



Yüklə 463 b.
tarix17.01.2018
ölçüsü463 b.
#20896


Introduction to Mycology

  • General Mycology Lecture 1

  • Pl P 421/521


What is a fungus?

  • A eukaryotic, heterotrophic organism devoid of chlorophyll that obtains its nutrients by absorption, and reproduces by spores.

  • The primary carbohydrate storage product of fungi is glycogen.

  • Most fungi have a thallus composed of hyphae (sing. hypha) that elongate by tip growth





Carl Linnaeus (1707-1778) the “Father of Taxonomy”

  • Carl Linnaeus (1707-1778) the “Father of Taxonomy”

    • Minerals exist; plants exist and live; animals exist, live and sense.”
    • Plants without obvious sexual organs were classified in Class Cryptogamia (lichens, fungi, mosses, ferns)
  • Fungi are primitive plants under this classification of organisms.





Modern Classification

  • At least 7 kingdoms are now recognized:

    • Eubacteria, Archaebacteria, Animalia, Plantae, Eumycota, Stramenopila (Chromista), Protoctista (Protozoa, Protista)




Fungi versus fungi

  • fungus” is used inclusively for a heterogenous group of organisms that have traditionally been studied by mycologists

  • Fungi” refers to the organisms in the Kingdom Fungi, the true fungi, also called the “Eumycota



Kingdom Fungi

  • Kingdom Fungi

  • Phyla: Chytridiomycota

      • Zygomycota
      • Glomeromycota
      • Ascomycota (inc.Deuteromycetes)
      • Basidiomycota




Kingdom Stramenopila (Chromista)

  • Kingdom Stramenopila (Chromista)

  • Phyla: Oomycota

  • Hyphochytriomycota

  • Labyrinthulomycota

  • Protists (Protoctists)

  • Phyla: Plasmodiophoromycota

  • Dictyosteliomycota

  • Acrasiomycota

  • Myxomycota



Hierarchical Classification

  • Hierarchical Classification

  • Kingdom Fungi

  • Phylum Basidiomycota

  • Class Basidiomycetes

  • Order Agaricales

  • Family Agaricaceae

  • Genus Agaricus

  • Species:

  • Agaricus campestris L.



Agaricus campestris L.

  • Agaricus is the genus

  • campestris is the specific epithet

  • The genus + species is the Latin binomial; note that the genus and species are in italics (or underlined), the genus is capitalized and the species epithet is in lower case

  • L. stands for Linnaeus, the authority

  • Agaricus campestris is the type species of the genus



Agaricus bisporus (Lange) Imbach



Nomenclature

  • Nomenclature: the “allocation of scientific names to the units a systematist considers to merit formal recognition.” (Hawksworth et al., 1995. The Dictionary of the Fungi). 

  • The nomenclature of fungi is governed by the International Code for Botanical Nomenclature, as adopted by the International Botanical Congress.



Typological Species Concept

  • "Species are as many as were created in the beginning by the Infinite."   (Linnaeus, 1758)

  • Each species represented by a type specimen, designated in the original description and deposited in a recognized collection (eg., herbarium)

  • The name is tied to the type specimen

  • The type specimen is not necessarily typical of the entire species!



How are fungi named?

  • To determine the correct name for a taxon, certain steps must be followed, including:

    • Effective publication
    • Valid publication
      • Description or diagnosis in Latin
      • Clear indication of rank
      • Designated type


How many species of fungi exist?



Estimating the number of fungal species

  • Hawksworth, D. L. (1991). The fungal dimension of biodiversity: magnitude, significance, and conservation. Mycological Research 95: 641-655

  • Hawksworth, D.L. (2001) The magnitude of fungal diversity: the 1.5 million species estimate revisited. Mycological Research 105 (12): 1422-1432.





Fungi are ancient

  • Major fungal lineages are ancient, perhaps emerging one billion years ago

  • Fungi were present before the emergence of animals and vascular plants





Associations

  • Fungi form symbiotic relationships with a number of organisms:

    • Lichens
    • Mycorrhizas
    • Endophytes


Decomposers

  • As saprotrophs, particularly as decomposers, fungi are essential components of the carbon cycle and are among the few organisms that can break down lignin



Pathogens

  • Fungi are important as pathogens of animals and plants.

    • Over 70% of all plant diseases are caused by fungi








Yüklə 463 b.

Dostları ilə paylaş:




Verilənlər bazası müəlliflik hüququ ilə müdafiə olunur ©genderi.org 2024
rəhbərliyinə müraciət

    Ana səhifə