Presentation is loading. Please wait.

Presentation is loading. Please wait.

Myco = Fungus logy = Study. إعــــــداد الطــــــــــلاب سوزان عبدالحكم إيمان ناصرأحمـد أسماء عبــــــادة تحت إشراف الدكتور/ عبدالدايم أبوالفتوح شريف.

Similar presentations


Presentation on theme: "Myco = Fungus logy = Study. إعــــــداد الطــــــــــلاب سوزان عبدالحكم إيمان ناصرأحمـد أسماء عبــــــادة تحت إشراف الدكتور/ عبدالدايم أبوالفتوح شريف."— Presentation transcript:

1 Myco = Fungus logy = Study

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

3 Mycology : is a branch of science which concentrate on studying fungi. 1. General Characters 2. Nutrition 3. Economic Importance 4. Reproduction 5. Classification

4 1- General Characters Eukaryotic Organisms (i.e true nucleus) Non-Vascular Organisms Non-motile except few fungi Vegetative body may be: unicellularFilamentous Septated Non-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 Reproduction Sexual Asexual Vegetative

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

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 : EndomycorrhizaeEctomycorrhizae Fungus doesn’t form sheath around the roots Fungus penetrate the cells of cortex without penetrating the cell membrane Ex. Zygomycota Fungus form a sheath around the root with hyphal grow through the soil which increase the surface area Fungus penetrate between cells of cortex Ex. Basidiomycota and Ascomycota

11 Lichens Symbiotic relation between fungus and algae Most are Ascomycota,few are Basidiomycota Lichens uses 1.Lichens break down rocks into soil 2.Food source for some animals 3.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 Harmful Cause human,animal, plant disease directly or their toxins Cause rot of food Can destroy manufactured good Useful Yeast bread & brew Antibiotics penicillin Steroids and Hormons Stinky Cheeses Source of organic compost Source of food Experimental importance as: Easily cultured, take little space, multiply rapidly, short life cycle Study metabolic pathways Study growth, development, differentiation Microbial assay of vitamins and amino acids Study mechanism of cell division and development 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 : plasmogamykaryogamymeiosis Cell fusion Nuclear fusion 2N 1N reduced to

14 1n Haploid number of chromosomes 2n Diploid number of chromosomes Meiosis

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

16 Methods of plasmogamy: Gametangial contact Gametangial copulation Spermatization Gametangial contact: The male and female gametangia come into contact with each other, and the male nuclei from male antheridium are transferred into the female oogonium either; through 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. antheridiumoogonium egg

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 - + 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 suspensor

18 Spermatization 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 spermatia Receptive hyphae 1.The sex organs are called gametangia which may be differentiated into antheridium & oogonium and produce different sex gametes 2.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, surface: shape: number of cells: arrangement: smooth roughspiny sphericalneedle pear kidney ovoid spindle fusiform unicellularbicellular multicellular solitarychaincluster

20 According to manner by which spores are borne on the mycelium, there are two types: Sporangiospores Conidia 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 acervulus pycnidium sporodocium

23 C. Vegetative: 1.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 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 structureSexual reproduction 1.Somatic structure: PlasmodiumRudimentary mycelium FilamentousUnicellular (Yeast)

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

29 Classification of true moulds: Chytridomycota Oomycota ZygomycotaAscomycota Basidiomycota Deuteromycota

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 oosphere antherozoid fertilization zoosporangium Meiosis

31 Oomycota Reproduce sexually by oogonia eggs The mycelium is non septated except under sexual and asexual organs Reproduce asexually by zoospores.

32 Zygomycota Reproduce sexually by zygospore The mycelium is non septated except 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 septated with a very characterized swelling called clamp connection which have a role in nuclear migration Reproduce asexually by conidia Lacking motile spores

35

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


Download ppt "Myco = Fungus logy = Study. إعــــــداد الطــــــــــلاب سوزان عبدالحكم إيمان ناصرأحمـد أسماء عبــــــادة تحت إشراف الدكتور/ عبدالدايم أبوالفتوح شريف."

Similar presentations


Ads by Google