Kingdom fungi

   Define fungus : It is the eukaryotic, nucleated, spore bearing, achlorophyllous organism generally produces by sexually or asexually.

• The word fungi is first discorved by R.T.Moore.
• The study of fungus is called as Mycology. 
• The word Mycology were first used by M.J.Berkeley, 

   It is the member of eukaryotic organism. which is without stem, root, and leaves. It includes microorganisms like Yeast (unicellular), moulds (multicellular) as well as mushrooms. 

Diagram of fungi

   Fungi is the huge and important component of biosphere. Their are more than 100,000 of species have been found.  In the kingdom fungi include molds, mildew, mushrooms, yeasts, morels, smuts, rusts etc. 

• Characters of fungi 

• Thallus :

       The body of fungus is called as thallus. Which is without stem, root and leaves. A single thread like filaments structure is known as hypha. The hypha is made up of thin,transparent, tubular walled lined with the layer of protoplasms.

 ●   Types of thallus

1. Eucarpic thallus : The thallus is differentiated into vegetative part which absorb nutrients and reproductive part from reproductive structure such  thallus is known as eucarpic thallus.                             

     eg. Pythium. 

2. Holocarpic thallus : The thallus is does not show any differentiation on vegetative and reproductive structure such thallus is known as holocarpic thallus.

      Eg. Yeast.

1.Thallus in pythium  

2.Thallus in yeast

• Cell wall : 

        The cell wall is most important part of all organisms,plant , animal etc.cell wall is made up of two components i.e chitin or cellulose. The pigment like a melanin present in the cell wall of fungus for protect the fungus against ultraviolet radiation.  It is does not present on the mammalian cell so it is attractive target for antifungal agents. 

Fungal cell wall 

• Nutrition :

        nutrition is important for growth and development of plants and animals. Fungi are heterotropic in nature like a animal i.e they photosynthesis lacking they lack of chlorophyll so they can't manufacture their Own food from carbon dioxide and water. They absorb nutrient by osmosis via. cell wall . Most of the fungi are simbiont and parasites on other  organism. Fungi are most important in the ecosystem because of they release large amounts of carbon dioxide in in the atmosphere and continue their cycle.

Their are three types of nutrients according to  manner they food obtained

1. Saprobes : It is also known as saprosphytes. Thous organism which required dead organic matter to complete it's life cycle called saprobes. The hyphae  of the fungi absorb food material from dead organic matter.                                   e.g Mucor 

   

   Mucor 

         Their are two types of saprobes are 

a. Ectophytic saprophytes 

b. Endophytic saprophytes 

   

      a. Enctophytic saprophytes: The organism which grows on surface of organic matter. In this type the ectophytic mycellium haustoria are produced in epidermal cell.

       b. Endophytic saprophytes : The organism which grows inside the organic matter. The endophytic intracellular mycellium absorbs food from protoplasm. 

2. symbionts : The simbionts is also known as symbiosis. The two dissimilar organism live together in close association for mutual benifits called as symbiosis.

  e.g  Lichen, Mycorrhiza.

Lichen 

•  Lichen show the mutualism. 

• The show mutualism with photosynthetic algae or cyanobacteria. 

3. Parasite:

          The organism which completely depend on their hosts, for food called parasites. Some parasites fungi are pathogenic i.e harmful to the host including species that infect human lungs and species that are responsible for about 70% to 80% plant disease. 

       Their are four types of parasite on the basis of degree of parasitism.

a.obligate parasites 

b.Non- obligate parasite

c.Facultative saprohytes 

d.facultative parasites

a.obligate parasites: It is also known as biotrophs. The organism which can't live without living host or tissue for complete their life cycle.  This parasites can't live on the dead or artificial food material.

     e.g  Rust, viruses 

Viruses

b.Non-obligate parasite: It is also known as necrotrophs. The organism when kill the tissue in advance of penetration and then live on it thus parasite called as non obligate parasite.

    e.g sclerotium 

Sclerotium

c. Faculative saprophytes : This organism are parasites on their life cycle for certain conditions, but they can live /survive on dead organic matter in absence of living host. 

    e.g smut

Smut

d.Faculative parasites : This organism are saprophytes in their mode of life cycle under certain condition. They are parasites on suitable host plant.  e.g pythium,phytopthora 

Pythium

       Their are two types of parasite on the basis of location

a. Endoparasite
b. Ectoparasite

a Endoparasite: The organism which live inside the host at various sites. 

b. Ectoparasite: The organism which feed on external surfaces of the host.

 ●Reproduction in fungi

     It is the characteristic feature of all organisms for continuation of it's generation. 
    
     It is the biological process in which, new 'organism ' are produce by its 'parents '.

     Reproduction ensure the continuity of species generation after generation.

     The fungi reproduce by spore.

    In fungi reproduction is complex it takes place either by sexually or asexually. In some fungi reproduction is carried out by sexually or asexually. 
   e.g Reproduction in bread molds is carried out by sexually or asexually. 

Reproduction in fungi 

      In fungi three types of reproduction are seen.

1. Vegetative Reproduction 
2. Sexual Reproduction 
3. Asexual Reproduction

 

1. Vegetative Reproduction :

           Vegetative Reproduction is the most common type of reproduction in fungi .In vegetative reproduction the new individual are from without production of the spore.

     •Method of vegetative Reproduction 

 a. Fragmentation 

 b. Binary fission 

 c. Budding

 d. Production of vegetative spore

a. Fragmentation : 

     

      Fragmentation is the most important 

mechanism that takes place in multicellular animal.

     Fragmentation is seen in various type of fungi.

     In fungi mycellium and each fragment grows into a new individual the hyphae breaks up into their component cell as oidia  / orthospore which like a 

spore.

       Chamydospore is the process in which cell become enveloped in a thick wall before separate from other hyphal cell
       e.g oidia of pawdery mildew.

Oidia of powdery mildew 

b. Binary fission : 

        It is a simple type of Reproduction, in which two somatic cell fused together and from doughter cell. The parent cell divided into two by the formation of constriction of  divider. 

  e.g  Yeast or True fungi 

Binary fission in Yeast 

c. Budding :

         In budding unequal divisions takes place. It is a small outgrowth of parent cell which is initially attached to the parent cell but later get separated and mature into new organism. In budding new individual form by mitosis.

 e.g Rust and small fungi 

Budding 

d. Production of vegetative spore : 

    • chlamydospore : These cell are formed from hyphae cell of old mycelium envelope by a thick cell wall , which latter on separates from parent hyphae behave as resting spore. 

  e.g fusurium spp.

2 .Asexual Reproduction through spore

Spore: It is the unit of sexual and asexual reproduction for dispersal and survival of the species.

    Fungi produce spore as a result of sexual and asexual reproduction. Fungi produce large amount of spore.

Their are two type of asexual spore

a.Endogeneous 

b.Exogeneous 

a.Endogeneous:

       The spore which is formed within the special sac by the division of protoplasm. The spore producing cell called as asparangium. This spore may be motile or non-motile.  

e.g •sporangiospores 

      •Aplanospore

● sporangiospores :

       Sporangiospores are produced inside the sac of asparangium. It is a motile spore. The protoplasm of the sporangium divided into uninucleated or multinucleated bits by breaking the wall of sporangium. This spore is also known as zoospore  or swarmspore . This spore are motile because presence of flagella. This spore are usually kideny shape. 

Sporangiospores

 

●Aplanospores: 

         The non-motile spore produce inside the sac of sporangium. This spore are non-motile because of absence of flagella. This spore are lack of nucleus and two layered cell wall.

e.g Mucor, Rhizopus. 

Spore in Rhizopus 

b.Exogeneous:

        This spore are produce outside the sporophores this spore is known as exogeneous spore.
 e.g •conidia
       •oidia 

●conidia:

        It is produce by asexually which is non motile. Some time conidia  produce inside the cell but at maturity they will be exposed to the external environment.  This spore are produce on specialized hyphae spore cell called as conidiphores. This spore are varying widely in shape, colour and size. The large spore conidia called macroconidia.The small one is called as microconidia . 

     e.g Alternaria

Conidia

●Oidia :

      Oidia is also a asexual spore. These spore are rectangular in shape. This spore are born on a very simple hyphae. This spore produce asexually in the chain from on the stalk called as oidiosphore.

e.g oidia in powdery mildew.

Life cycle of spores 

Oidia 

2. Sexual Reproduction: 

       Sexual reproduction is the important source of genetic variability allow  the fungus to adapt new environments.  The large number of fungi reproduce sexually. Imperfecti or Deuteromycetes are those fungi which lack sexual reproduction .

          The union of two nuclei or gametes of 

opposite sex this gamete is unisexual i.e haploid.

           Their are two phase are found in fungi life cycle i.e haploid and diploid.

            When two mating types are present in the same mycelium it is called as homothallic or self fertile.when the mycelia called heterothallic.

             The reproduction in fungi consist of three different phase are.....

a. plasmogamy 

b. Karyogamy 

c. Meiosis

 a .plasmogamy :

           The fusion of two protoplast having two haploid nuclei together in the same cell. In this type two different type of nucleus are present in the same cell.

b.karyogamy :

            It is the fusion of two 'haploid' nuclear and form the result of plasmogamy I.e diploid nucleus. 

           It is also follows the plasmogamy. It contain two set of chromosome. The cell formed in the karyogamy is called as zygote.

C meiosis:

            It is the part of sexual reproduction. Meiosis is the form of nuclear division in which diploid number of chromosome reduce into haploid.   

            The sex organ in the fungi are called as gametatangia. Gamentangia form different sex cell called gamete or it contain one or more gamete nuclei.