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(pgs. 548-559)
Hyphae
Basidia
Mycorrhizae
Conidium
Mycelium
 A hypha (plural hyphae)
is a long, branching
filamentous cell of
a fungus, and also of
unrelated Actinobacteria.
In fungi, hyphae are the
main mode of vegetative
growth, and are collectively
called a mycelium.
Continue For More information on Hyphae
Continue To Basidia
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Generative hyphae are relatively
undifferentiated and can develop reproductive
structures. They are typically thin-walled,
occasionally developing slightly thickened
walls, usually have frequent septa, and may or
may not have clamp connections. They may be
embedded in mucilage or gelatinized
materials.
Skeletal hyphae are of two basic types, the
classical form is thick-walled and very long in
comparison to the frequently septate
generative hyphae, unbranched or rarely
branched, with little cell content. They have
few septa and lack clamp connections.
Fusiform skeletal hyphae are the second
form of skeletal hyphae. Unlike typical skeletal
hyphae these are swollen centrally and often
exceedingly broad, hence giving the hypha
afusiform shape.
Binding hyphae are thick-walled and frequent
branched. Often they resemble deer antlers or
defoliated trees because of the many tapering
branches.
A basidium (pl., basidia) is a
microscopic, spore-producing structure
found on the hymenophore of fruiting
bodies of basidiomycete fungi. The
presence of basidia is one of the main
characteristic features of
the Basidiomycota. A basidium usually
bears four sexual spores called
basidiospores; occasionally the number
may be two or even eight. In a typical
basidium, each basidiospore is borne at
the tip of a narrow prong or horn called
a sterigma (pl. sterigmata), and is
forcibly discharged upon maturity.
 The word basidium literally means little
pedestal, from the way in which the
basidium supports the spores. However,
some biologists suggest that the
structure more closely resembles a club.
An immature basidium is known as
a basidiole.
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 Most basidiomycetes have single
celled basidia (holobasidia), but in
some groups basidia can be
multicellular (a phragmobasidia).
For instance, rust fungi in the
order Uredinales have four-celled
phragmobasidia that are
transversely septate; some jelly fungi
in the order Tremellales have fourcelled phragmobasidia that are
cruciately septate. Sometimes the
basidium (metabasidium) develops
from a probasidium, which is a
specialized cell which is not
elongated like a typical hypha. The
basidium may be stalked or sessile.
Continue to Mychorrhiza
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A mycorrhiza (Greek for fungus roots coined by
Frank, 1885[1]; typically seen in the plural
forms mycorrhizae or mycorrhizas) is
a symbiotic (occasionally weakly pathogenic)
association between a fungus and the roots of
a plant.[2] In a mycorrhizal association, the fungus may
colonize the roots of a host plant, either intracellularly
or extracellularly. It is an important part ofsoil life.
This mutualistic association provides the fungus with
relatively constant and direct access to mono- or
dimeric carbohydrates, such
as glucose and sucrose produced by the plant
inphotosynthesis.[3] The carbohydrates are
translocated from their source location (usually leaves)
to the root tissues and then to the fungal partners. In
return, the plant gains the use of themycelium's very
large surface area to absorb water and mineral
nutrients from the soil, thus improving the mineral
absorption capabilities of the plant roots.[4] Plant roots
alone may be incapable of taking
up phosphate ions that are immobilized, for example,
in soils with a basic pH. The mycelium of the
mycorrhizal fungus can however access these
phosphorus sources, and make them available to the
plants they colonize.[5] The mechanisms of increased
absorption are both physical and chemical.
Mycorrhizal mycelia are much smaller in diameter
than the smallest root, and can explore a greater
volume of soil, providing a larger surface area for
absorption. Also, the cell membrane chemistry of
fungi is different from that of plants. Mycorrhizae are
especially beneficial for the plant partner in nutrientpoor soils.
 Mycorrhizal plants are often
more resistant to diseases, such
as those caused by microbial
soil-borne pathogens, and are
also more resistant to the effects
of drought. These effects are
perhaps due to the improved
water and mineral uptake in
mycorrhizal plants.
 Mycorrhizae form
a mutualistic relationship with
the roots of most plant species
(and while only a small
proportion of all species has
been examined, 95% of these
plant families are predominantly
mycorrhizal).[6]
Conidia, sometimes
termed conidiospores, are asexual, nonmotile spores of a fungus; they are also
called mitospores due to the way they
are generated through the cellular
process of mitosis. They are haploid cells
genetically identical to the haploid
parent, can develop into a new organism
if conditions are favorable, and serve
in biological dispersal.
 Asexual reproduction in Ascomycetes
(the Phylum Ascomycota) is by the
formation of conidia, which are borne on
specialized stalks calledconidiophores.
The morphology of these specialized
conidiophores is often distinctive of a
specific species and can therefore be
used in identification of the species.
 The terms "microconidia" and
"macroconidia" are sometimes used.
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 There are two main types
of conidium development.
 blastic conidiogenesis,
where the spore is already
evident before it separates
from the
conidiogenic hypha which
is giving rise to it, and
 thallic conidiogenesis,
where first a cross-wall
appears and then the thus
created cell develops into a
spore.
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A conidium may form germ tubes
(germination tubes) and conidial anastomosis
tubes (CATs) in specific conditions. These two
are some of the specialized Hyphae that are
formed by fungal conidia. Conidial
anastomosis tubes are morphologically and
physiologically distinct from germ tubes and
are under separate genetic control. The biology
of conidial anastomosis tubes is not
completely understood. After conidia are
induced to form conidial anastomosis tubes,
they grow homing toward each other, and
eventually they fuse. Once fusion happens, the
nuclei can pass through fused CATs. These are
events of fungal vegetative growth and not
sexual reproduction. Fusion between these
cells seems to be important for some fungi
during early stages of colony establishment.
The production of these cells has been
suggested to occur in 73 different species of
fungi.
 Mycelium (plural mycelia) is
the vegetative part of a fungus,
consisting of a mass of branching,
thread-like hyphae. The mass of
hyphae is sometimes called shiro,
especially within the fairy ring fungi.
Fungal colonies composed of
mycelia are found in soil and on or
in many other substrates. Typically a
single spore germinates into a
monokaryotic mycelium which
cannot reproduce sexually; when
two compatible monokaryotic
mycelia join and form a dikaryotic
mycelium, that mycelium may
form fruiting bodies such
as mushrooms. A mycelium may be
minute, forming a colony that is too
small to see, or it may be extensive
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One of the primary roles of fungi in an
ecosystem is to decompose organic
compounds. Petroleum products
and pesticides that can be contaminants of soil
are organic molecules. Fungi therefore should
have potential to remove such pollutants from
the soil environment, a process known
as bioremediation.
Mycelial mats have been suggested (see Paul
Stamets) as having potential as biological
filters, removing chemicals
and microorganisms from soil and water. The
use of fungal mycelia to accomplish this has
been termed "mycofiltration", although there
is no reason to suspect that the process is any
different from that of bioremediation using
fungi.
Some Mycelium has symbiotic property with
many plants. This opens the door to soil
supplementation to improve crop yields.
Mycelium, spread on logging roads acts as a
binder holding new soil in place and
preventing washouts until woody plants can be
established.
 Sporangia:
A sporangium (pl., sporangia) is
a plant, fungal, or algal structure
producing and containing spores .
 Rhizoids: Rhizoids are a structure
in plants, fungi and some other
organisms (e.g. some sponges) that
functions like a root in support or
absorption.
 Stolons: Stolons are horizontal
connections between organisms.
They may be part of the organism,
or of its skeleton;
typically, animalstolons are external
skeletons.