Presentation on theme: "ULTRASTRUCTURE 1) Spores"— Presentation transcript:
1 ULTRASTRUCTURE1) SporesFungi reproduced by means of spores (both sexually or asexually).Moulds, spores germinate to produce branching filaments called hyphae which may have septa (divided into cells / crosswalls) or not (coenocytic / aseptate / non-septate).The cells of the hyphae may be uninucleate or multinucleate. Mass of hyphae is called mycelium.
3 ULTRASTRUCTURE 1) Spores Different types of septum. Dolipore septum – found in most complex fungi; have a central apparatus in the form of a barrel-shaped inflation surrounded by a perforated membrane. This perforated(berlubang) pore is large enough to permit passage of nuclei and other organelles.In yeasts, a spore germinates to produce round, oval or elongated single cells that reproduce mostly by budding (some by fission) and formed moist or mucoid colonies.
5 ULTRASTRUCTURE 2) Nucleus - Nucleus is bounded by a nuclear membrane and consisting of RNA. (?Euk /?Prok)- In the cytoplasm : mitochondria, vacuoles, vesicles, endoplasmic reticulum, ribosomes, microbodies, microtubules, crystals, glycogen, golgi / dictyosome).3) Cell Wall- The cell wall constitutes of polysaccharides (chitin, cellulose, glucan, galactose, mannose, galactoseamine) proteins, lipids.
6 ULTRASTRUCTURE 4) Mycellium Mass of hyphae - called the mycelium. Different forms of mycelia - Rhizomorph, Haustoria, PlectenchymaThick forms of mycelium is called the rhizomorph which looks like the root tip (has a thick, hard cortex and a growing tip, resistant to adverse (buruk) conditions but remain dormant (x active) until conditions are favourable, usually produced in complex fungi such as Basidiomycete).
7 Mycellium of parasitic fungi grow on the surface of host plants and called haustoria which are used to obtain nourishment from host.A specialised hyphal invagination of plant cells.
8 ULTRASTRUCTURE 4) Mycellium Plectenchyma are mycelium loosely (longar) compact woven (anyaman) tissues which are different from the usual loose hyphae and they are of two types:the prosenchyma (loosely weaved hyphae and parallel to each other);the pseudoparenchyma (closely packed oval cells).Both form the stromata and sclerotium.Stromata are compact somatic structures which act as cushionSclerotium are hard resting body resistant to unfavourable conditions and may remain dormant (x aktif) for a long time until ready to germinate.
9 GROWTH CONDITIONS1) Temperature Most fungi grow best between 0oC to 30oC of which the optimum temperature range is 20 to 30oC. Thermophilic species can grow to above 50oC or a minimum of 20oC. 2) pH The pH is pH6. 3) Light Light is not required but some light is essential for sporulation in many species. Important role in spore dispersal (penyebaran).
10 NUTRITION Saprobe or Parasite They are either saprophytic or parasitic.An Obligate saprobe is incapable of causing disease on living organisms as they live on dead organic matter.A Facultative parasite or Facultative saprobe can cause disease or live on dead organic matter depending on circumstances.An Obligate parasite must only feed on living organisms.
11 NUTRITION2) NutrientsFungi do not possess chlorophyll and are not able to make their own food.But if given carbohydrates (e.g. glucose / maltose), most of them can make their own proteins from organic or inorganic sources.Most fungi need C, O, H, N, P, K, Mg, S, B, Mn, Cu, Mo, Fe, Zn and Ca (not so for all fungi).Glucose is the best source for C.Ammonium compounds and nitrates are the best sources for N.Fungi store excess foods in the form of glycogen or lipids.