Mycology

1. Mycology Myco = Fungus logy=Study

2. إعــــــداد الطــــــــــلاب أحمــد سمير فتحي محمد ماهر محمود أحمد محمــد نجيب سوزان عبدالحكم إيمان ناصرأحمـد أسماء عبــــــادة محمد إبراهيم المهدي • تحت إشراف • الدكتور/ عبدالدايمأبوالفتوح شريف • قسم النبات – كلية العلوم – جامعة المنصورة • (2008 – 2009)

3. Introduction Mycology : is a branch of science which concentrate on studying fungi. • General Characters • Nutrition • Economic Importance • Reproduction • Classification

4. 1- General Characters • Eukaryotic Organisms (i.e true nucleus) • Non-Vascular Organisms • Non-motile except few fungi • Vegetative body may be: unicellular Filamentous Non-Septated Septated

5. Like plants, have alternation of generation • cell wall similar in structure of plant but • differ in chemical composition • Plant C.W. Cellulose + lignin • Fungi C.W. Chitin • Fungi are Heterotrophic organisms • Growth by apical elongation of hyphal tip • Food stored as glycogen but plant as starch • Cell membrane in animal cholesterol • in Fungi ergosterol

6. Fungi produce exoenzymes to digest food then ingest it • Reproductive Structures are differentiated from somatic structures • Cytoplasmic ultrastructures similar to plant cells , but differ in kinds or organelles

7. Most fungi have very small nuclei , with little repetative DNA

8. 2- Nutrition in fungi Symbiotic Saprophytes Parasites • Saprophytes : 1- use non - living organic materials 2- important in recycling C,N and essential mineral nutrients

9. Parasites : 1- use organic materials from living organisms , causing diseases to them 2- they have a wide range of hosts as diatoms , fungi , plants ,animals , human . • Symbiotic : 1- fungi that have a beneficial symbiotic relationship with other living organisms Ex : Mycorrhizae Lichens Commensalism

10. Mycorrhizae It is associations of fungi with plants roots • Types of Mycorrhizae :

11. Lichens • Symbiotic relation between fungus and algae • Most are Ascomycota ,few are Basidiomycota • Lichens uses • Lichens break down rocks into soil • Food source for some animals • Source for dyes , tweed Commensalism • One organism uses another to get better position • No physiological interaction • Maybe for photosynthesis or reproductive advantages

12. 3-Economic Importance to

13. 4- Reproduction • Types of reproduction: Sexual Asexual vegetative a. Sexual: - Involve the union of two compatible nuclei with a subsequent meiotic division - All sexual fungal life cycles consists of : plasmogamy karyogamy meiosis reduced to Cell fusion Nuclear fusion 2N 1N

14. Meiosis Nuclei or Gametes (n) Zygote (2n) fungal life cycle Plasmogamy (n) karyogamy (n+n) • 1nHaploid number of chromosomes • 2n Diploid number of chromosomes

15. The two fusing gametes may be: 1. Morphologically the same, they are called isogametesand the process of fertilization is called isogamous 2. Differ in size and structure, they are called heterogametes and the process of fertilization is called heterogamous Anisogamy oogamy .Differ in everything The fussing gametes are morphologically the same but differ in size .As between antheridium and oogonium or ascogonium antheridium

16. Methods of plasmogamy: Gametangial contact Gametangial copulation Spermatization • Gametangial contact: oogonium antheridium • The male and female gametangia come into contact with each other, and the male nuclei from male antheridium are transferred into the female oogoniumeither; through egg a pore at the point of their contact or through a tube called fertilization tube arise from antheridium to oogonium, then plasmogamy & karyogamy occur inside the oogonium.

17. Gametangial copulation: • Fusion occurs between the entire content of the two gametangia by one of the following ways: a. Contents of one gametangium is transferred to the other through a pore at the point of their contact suspensor b. The content of the two - + gametangia fuse by the dissolution of their contact walls, leading to the formation of a common cell, in which the content of the two gametangia mix

18. Spermatization spermatia • Occurs by the transfer of spermatia (unicellular – non motile male cells) by wind, water or insects to a special receptive hyphae on the female gametangium Receptive hyphae Notes • The sex organs are called gametangia which may be differentiated into antheridium & oogonium and produce different sex gametes • Some fungi are: homothalic (single mycelium reproduce sexually), others are heterothalic (two mycelia reproduce sexually)

19. b.Asexual: • Asexual reproduction takes place by spores • Fungal spores are variable in:colour, size, rough spiny smooth surface: pear spherical needle shape: kidney spindle ovoid fusiform unicellular bicellular number of cells: multicellular arrangement: solitary chain cluster

20. According to manner by which spores are borne on the mycelium, there are two types: SporangiosporesConidia • Sporangiospores: • Asexual spores produced internally in a sac like structure called sporangium, borne on specialized hyphae called sporangiophore • Sporangiospores may be: motile or non motile Motile • Called zoospores • The sporangia called zoosporangia • They may have one or two flagella similar or • They may fixed anteriorly or posteriorly or different (tinsel, whiplash) ventrally

21. Non motile • Called a planospores • Are disseminated by wind current

22. Conidia: • Asexual non motile spores produced externally on a special hyphae called conidiophore • Conidia may formed singly (phytophthora) or in chain (penicillium) • Conidiophores may be free from each other or aggregated to form the following compound structures pycnidium acervulus sporodocium

23. C.Vegetative: • Fragmentation: The mycelium breaks up into fragments, each fragment germinate into a new individual under favorable conditions 2. Oidia: The hyphae break up into small oval or rounded segments hyphae 3. Chlamydospore: Certain cells of hyphae become thick walled chlamydospore

24. 4. Fission: In unicellular true fungi (Yeast), the vegetative cell splits into two equal daughter cells 5. Budding: As in Yeast, the vegetative cell produces a small out growth (bud) which is finally separated from the mother cell and form a new cell

25. 6. Sclerotia: Hardened & resistant bodies Some definitions • Sporangium: Asexual sac like structure, carried on special hyphae called sporangiophores containing several sporangiospores • Sporangiospores: Asexual spores produced internally in a sac like structure called sporangium, borne on specialized hyphae called sporangiophore.

26. Conidia: Asexual non motile spores produced externally on a special hyphae called conidiophore • Conidiosporangium: Asexual spores, which may be germinate directly as conidium or sporangium (give several spores which release and germinates)

27. 5- Classification of fungi • Based on: Somatic structure Sexual reproduction • Somatic structure: Plasmodium Rudimentary mycelium Filamentous Unicellular (Yeast)

28. 2.Sexual reproduction: • Fungi are classified as following: Kingdom: Mycota Subkingdom: Myxomycota Subkingdom: Eumycota (True Moulds) (Slime moulds) • The vegetative phase is plasmodium • Classified according to the method of sexual reproduction Plasmodium: • Slimy, naked, multinucleate mass of protoplasm

29. Classification of true moulds: Chytridomycota Deuteromycota Oomycota Basidiomycota Zygomycota Ascomycota

30. Chytridomycota • Mostly unicellular fungi, occurring in several habitats as soil, roots, rumen of cows • Asexual & sexual spores are produced in sporangia and release as zoospores zygote oospore Meiosis oosphere zoosporangium fertilization antherozoid

31. Oomycota • Reproduce sexually by oogoniaeggs • The mycelium is non septatedexcept under sexual and asexual organs • Reproduce asexually by zoospores .

32. Zygomycota • Reproduce sexually by zygospore • The mycelium is non septatedexcept under sexual and asexual organs • Reproduce asexually by sporangia or conidia • Lacking motile spores

33. Ascomycota • They have ascospore borne inside ascus • The mycelium is septated • Reproduce asexually by conidia

34. Basidiomycota • They have basidiospore borne externally on a basidium • The mycelium is septatedwith a verycharacterizedswelling calledclampconnectionwhich have a role innuclear migration • Reproduce asexually byconidia • Lacking motile spores

36. Deuteromycota • Called fungi imperfecti • Don’t have sexual state in their life cycle • The mycelium is septated