1) Fungi can have mutualistic or parasitic relationships with other organisms. Mutualistic relationships include mycorrhizal associations between fungi and plant roots that benefit both organisms.
2) Lichens are a mutualism between a fungus and an alga or cyanobacterium. The alga provides carbohydrates while the fungus provides minerals and structure.
3) Fungi play important ecological roles through mycorrhizal and lichen relationships and can be used as indicators of air pollution.
This maybe of help for UG+PG Botany students studying mycology. It's about the general account of class Chytridiomycetes. Good for quick revision and information.
*Critics are very welcomed*
Heterothallic species have sexes that reside in different individuals. . The term is applied particularly to distinguish heterothallic fungi, which require two compatible partners to produce sexual spores, from homothallic ones, which are capable of sexual reproduction from a single organism.
Fungi are a kingdom of usually multicellular eukaryotic organisms that are heterotrophs (cannot make their own food) and have important roles in nutrient cycling in an ecosystem. Fungi reproduce both sexually and asexually, and they also have symbiotic associations with plants and bacteria.
A chemical substance that is produced in one portion of an organism and moves by diffusion or transport to another portion of same individual or to other individual of same species where it induce specific response is called a hormone.
This maybe of help for UG+PG Botany students studying mycology. It's about the general account of class Chytridiomycetes. Good for quick revision and information.
*Critics are very welcomed*
Heterothallic species have sexes that reside in different individuals. . The term is applied particularly to distinguish heterothallic fungi, which require two compatible partners to produce sexual spores, from homothallic ones, which are capable of sexual reproduction from a single organism.
Fungi are a kingdom of usually multicellular eukaryotic organisms that are heterotrophs (cannot make their own food) and have important roles in nutrient cycling in an ecosystem. Fungi reproduce both sexually and asexually, and they also have symbiotic associations with plants and bacteria.
A chemical substance that is produced in one portion of an organism and moves by diffusion or transport to another portion of same individual or to other individual of same species where it induce specific response is called a hormone.
FUNGI - ROLE IN AGRICULTURE,MEDICINE & COMMERCIAL PRODUCTS. ChhanKumarkalita
TOPIC: FUNGI - ROLE IN AGRICULTURE,MEDICINE & COMMERCIAL PRODUCTS.
Presented By: Chhan kumar kalita
B.Sc. in Botany, Dept of Botany, B.P. Chaliha College, Nagarbera
M.Sc. in Botany, Dept of Botany, Nowgown College (Autonomous)
Introduction,In some fungi ,true sexual cycle comprising of nuclear fusion and meiosis is absent.
These fungi derive the benefits of sexuality through a cycle know as parasexuaL cycle.
First Reported by- Gudio Pontecorvo and J.A.Roper(1952)
Parasexual cycle was reported in
Aspergillus nidulans,the imperfect stage of Emericella nidulans.
Since then parasexual cycle has been discovered not only in several members of Deutromycetes but also in fungi belonging to Ascomycetes and Basidiomycetes.
DEFINETION - Parasexuality is defined as a cycle in which Plasmogamy, Karyogamy and Meiosis [Haploidization] take place in sequence but not at a specified time or at specified points in the life cycle of an organism.
Generally parasexual cycle occurs in those fungi in which true sexual cycle does not take place.
Parasexualcycle also know as Somatic recombination. PASEXUALITY ALSO REPORTED IN SOME ORGANISMS- Aspergillus nigar, Penicillium crysogenum, STEPS OF PARASEXUAL CYCLE - 1) ESTABLISHMENT OF HETEROKARYOSIS, 2) Formation of Heterozygous DIPLOIDS, 3) occasional mitotic crossing-over during multiplication of diploid nuclei, 4)occasional haplodization through aneuploidy , COMPARISION BETWEEN SEXUAL AND PARASEXUAL CYCLE, IMPORTANCE OF PARASEXUALITY, C0NCLUSION
Fungi get their nutrition by absorbing organic compounds from the environment. Fungi are heterotrophic: they rely solely on carbon obtained from other organisms for their metabolism and nutrition. Fungi have evolved in a way that allows many of them to use a large variety of organic substrates for growth, including simple compounds such as nitrate, ammonia, acetate, or ethanol. Their mode of nutrition defines the role of fungi in their environment.
Fungi obtain nutrients in three different ways:
They decompose dead organic matter. A saprotroph is an organism that obtains its nutrients from non-living organic matter, usually dead and decaying plant or animal matter, by absorbing soluble organic compounds. Saprotrophic fungi play very important roles as recyclers in ecosystem energy flow and biogeochemical cycles. Saprophytic fungi, such as shiitake (Lentinula edodes) and oyster mushrooms (Pleurotus ostreatus), decompose dead plant and animal tissue by releasing enzymes from hyphal tips. In this way, they recycle organic materials back into the surrounding environment. Because of these abilities, fungi are the primary decomposers in forests.
They feed on living hosts. As parasites, fungi live in or on other organisms and get their nutrients from their host. Parasitic fungi use enzymes to break down living tissue, which may cause illness in the host. Disease-causing fungi are parasitic. Recall that parasitism is a type of symbiotic relationship between organisms of different species in which one, the parasite, benefits from a close association with the other, the host, which is harmed.
They live mutualistically with other organisms. Mutualistic fungi live harmlessly with other living organisms. Recall that mutualism is an interaction between individuals of two different species, in which both individuals benefit.
FUNGI - ROLE IN AGRICULTURE,MEDICINE & COMMERCIAL PRODUCTS. ChhanKumarkalita
TOPIC: FUNGI - ROLE IN AGRICULTURE,MEDICINE & COMMERCIAL PRODUCTS.
Presented By: Chhan kumar kalita
B.Sc. in Botany, Dept of Botany, B.P. Chaliha College, Nagarbera
M.Sc. in Botany, Dept of Botany, Nowgown College (Autonomous)
Introduction,In some fungi ,true sexual cycle comprising of nuclear fusion and meiosis is absent.
These fungi derive the benefits of sexuality through a cycle know as parasexuaL cycle.
First Reported by- Gudio Pontecorvo and J.A.Roper(1952)
Parasexual cycle was reported in
Aspergillus nidulans,the imperfect stage of Emericella nidulans.
Since then parasexual cycle has been discovered not only in several members of Deutromycetes but also in fungi belonging to Ascomycetes and Basidiomycetes.
DEFINETION - Parasexuality is defined as a cycle in which Plasmogamy, Karyogamy and Meiosis [Haploidization] take place in sequence but not at a specified time or at specified points in the life cycle of an organism.
Generally parasexual cycle occurs in those fungi in which true sexual cycle does not take place.
Parasexualcycle also know as Somatic recombination. PASEXUALITY ALSO REPORTED IN SOME ORGANISMS- Aspergillus nigar, Penicillium crysogenum, STEPS OF PARASEXUAL CYCLE - 1) ESTABLISHMENT OF HETEROKARYOSIS, 2) Formation of Heterozygous DIPLOIDS, 3) occasional mitotic crossing-over during multiplication of diploid nuclei, 4)occasional haplodization through aneuploidy , COMPARISION BETWEEN SEXUAL AND PARASEXUAL CYCLE, IMPORTANCE OF PARASEXUALITY, C0NCLUSION
Fungi get their nutrition by absorbing organic compounds from the environment. Fungi are heterotrophic: they rely solely on carbon obtained from other organisms for their metabolism and nutrition. Fungi have evolved in a way that allows many of them to use a large variety of organic substrates for growth, including simple compounds such as nitrate, ammonia, acetate, or ethanol. Their mode of nutrition defines the role of fungi in their environment.
Fungi obtain nutrients in three different ways:
They decompose dead organic matter. A saprotroph is an organism that obtains its nutrients from non-living organic matter, usually dead and decaying plant or animal matter, by absorbing soluble organic compounds. Saprotrophic fungi play very important roles as recyclers in ecosystem energy flow and biogeochemical cycles. Saprophytic fungi, such as shiitake (Lentinula edodes) and oyster mushrooms (Pleurotus ostreatus), decompose dead plant and animal tissue by releasing enzymes from hyphal tips. In this way, they recycle organic materials back into the surrounding environment. Because of these abilities, fungi are the primary decomposers in forests.
They feed on living hosts. As parasites, fungi live in or on other organisms and get their nutrients from their host. Parasitic fungi use enzymes to break down living tissue, which may cause illness in the host. Disease-causing fungi are parasitic. Recall that parasitism is a type of symbiotic relationship between organisms of different species in which one, the parasite, benefits from a close association with the other, the host, which is harmed.
They live mutualistically with other organisms. Mutualistic fungi live harmlessly with other living organisms. Recall that mutualism is an interaction between individuals of two different species, in which both individuals benefit.
Organisms are classified by humans for convenience of reference. In the scheme of classification, mycologists may not give equal importance to the criteria available. And therefore, we find different schemes of classification
Lichens=(Algae+Fungi) Symbiotic Association (Phycobiont+ Mycobiont), Idealistic marriage, Pioneers species of Xerosere succession Shows Dual Nature, Trinity=(One Algae+Two Fungi), Natural farmers, it melt stone convert stone to soil particles
this presentation is about mycorrhiza. it is a benefitial association between fungi and roots of higher plants. in this presentation we will study about mycorrhiza and its types etc.
Lichens , types of lichens based on growth and habitat, importance of lichens, fungal habits and colonization strategies, Air borne fungi and micotoxins.
Along with bacteria, these are the most important Decomposers in the biosphere. They convert dead, organic matter into its inorganic components. Pathogenic/parasitc fungi have specialized hyphae called haustoria, which are used to invade the host's cells and create a nutrient pathway between fungus and host.
Lichens are very effective at absorbing nutrients directly from the atmosphere, and for this reason are very sensitive to smog.They are important primary producers in harsh environments such as tundra.
Several major taxa of fungi are generally recognized...
Chytridiomycota (the "chytrids")
Zygomycota (the black bread molds)
Ascomycota (the sac fungi)
Basidiomycota (the club fungi)
2. FUNGI AND ITS RELATIONSHIPS
WITH OTHER ORGANISMS
Mutualistics Relationship
Fungi and Plants: Mycorhizza, Lichen
Parasitic Relationship
Fungi and Animal or Insects
Fungi and Humans
3. MUTUALISM vs PARASITISM
Symbiosis: any situation where two different
species live together.
Mutualism – both partners benefit.
Parasitism – only one partner benefits; typically
reduces the fitness of other.
Commensalism – two species live together
without either harming the other, but where only
one partners benefit.
Mutualism and paratism were extensively
studied.
5. MUTUALISTICS RELATIONSHIP WITH
PLANTS
MYCORRHIZA
“Myco” meaning fungus, “Rhiza” meaning root.
Mycorrhiza is a mutualistic relationship between a
fungus in the soil and a plant root.
Characteristics:
1) Can increase uptake of plant nutrients such as
phosphorus and nitrogen especially when there is
a low concentration / insoluble form of it in the
soil.
2) Can assist nutrient uptake by plants from dilute
solutions.
7. Ectotrophic (sheating) Mycorrhiza
Typically associated with temperate trees.
Ex: Amanita muscaria (fly agaric) with birch or
pine.
Association: Mutualistic: fungus supplies plant
with NH3 and PO43- from soil, plant supplies fungus
with carbohydrates produced during
photosynthesis.
8. Ectotrophic (sheating) Mycorrhiza
Characteristics:
1) Fungus forms highly
developed sheath
around roots. Mycelial
strands extend into soil.
2) Intercellular invasion of
cortex to form Hartig’s
net.
3) Root hair formation
suppressed (mycelium
functional equivalent
of root hairs). Root
morphology altered.
9. Vesicular-arbuscular (V-A)
Mycorrhiza
Most widespread type of mycorrhiza.
Associated with borophytes, ferns,
spermatophytes (especially tropical trees).
Ex: Endogone spp. with grasses.
Association: Mutualistic: fungus supplies plant
with NH3 and PO43- from soil, plant supplies fungus
with carbohydrates produced during
photosynthesis (same as ectotrophic
mycorrhiza).
10. Vesicular-arbuscular (V-A)
Mycorrhiza
Characteristics:
1) No sheath. Fine hyphae
extend to soil.
2) Intracellular
penetration of middle
cortex. No Hartig’s net.
Fungus form
characteristics vesicles
and arbuscules.
3) Root hairs present. No
apparent alteration of
root morphology.
11. Orchidaceous Mycorrhiza
Unique to orchid.
Ex: Armillaria mellea (honey fungus) with
Gastropodia elata.
Association: Orchid parasitic on fungus.
Peletons degenerate and supply orchid with
sugars, vitamins and other nutrients obtained by
saprophytic action of fungus outside root.
12. Orchidaceous Mycorrhiza
Characteristics:
1) Same as V-A.
2) Intracellular
penetration of inner
cortex. Fungus forms
characteristics coils
(peletons).
3) ± root hairs.
13. Ericaceous Mycorrhiza
Associated with heather and related plants.
Includes Boletus and monotropa (bird’s nest
plant)
Association: Variable: achlorophyllous plant may
be parasitic on fungus (monotropa type).
Alternatively, mutualistic in heather type.
14. Ericaceous Mycorrhiza
Characteristics:
1) Variable form; loose
weft of hyphae
surrounds root
(heather) or definite
sheath (Monotropa).
2) Intracellular
penetration of outer
cortex. In Monotropa a
Hartig’s net may be
additionally present.
3) No root hairs, no
epidermal cells.
15. LICHENS
Mutualistic combination of an alga or blue-green
bacteria (cyanobacterium) with fungus.
ORGANISM
Mycobiont (fungus)
There are ascomycetes or Basidiomycetes (rarely).
They are ecologically obligate symbionts.
Phycobiont (alga or bacterium)
These are green algae (ex: Trebouxia, 70 % of all
lichens) or blue-green (ex: Nostoc).
They may be free living.
16. Main Features of Lichens
RELATIONSHIP BETWEEN ASSOCIATES
Alga (phycobiont) produces and secretes
carbohydrates
Fungus (Mycobiont) may supply minerals to the alga.
Uncertain, no experimental confirmation, phycobiont
may be able to absorb its own minerals from the
substrate.
This association probably enables both partners to
exploit habitat which would be unsuitable for either
alone.
STRUCTURE
There is often a highly organised thallus, with algae
forming a definite layer.
17. Three Types of Lichens
MORPHOLOGY
Crustose: crust like,
Ex: Xanthoria which is
the common yellowish
lichen on gravestone.
Foliose: Leaf like,
Ex: Parmelia which is
common in woodland.
Fruticose: Shrubby,
Ex: Cladonia which is
common on acid
heathland.
18. Lichens survive on bare rock, tree trunks,
inhospitable places.
Lichens growing on
a rock.
Lichens growing
on trees.
20. Ecology and Applications of
Lichens
Lichen killed as SO2 levels rise.
Used as indicator of atmospheric pollution. Lichens
are so efficient at absorbing nutrients from the air
that they can be used to monitor air quality because
some kinds do not survive in polluted air.
Breaking down rocks and starting the process of soil
formation.
Lichens or their products may be used as:
Dyes (Harris tweed)
Food (for reindeer herds)
Antimicrobial (Usnea)
Indicators (Litmus)