The document summarizes key aspects of Deuteromycota (imperfect fungi), including their morphology, reproduction, and classification. Some Deuteromycota are saprophytes, but many are plant and animal parasites that cause disease. They reproduce asexually through structures like conidiophores, conidia, and specialized fruiting bodies. Four classes are described based on reproductive structures: Hyphomycetes, Coelomycetes, Blastomycetes, and Deuteromycetes.

1. DEUTEROMYCOTINA

2. (i) Deuteromycetes occur mostly as saprophytes on a wide range of substrates, but a large
number of them are parasites on plants and animals (including humans) and cause a variety of
diseases.
(ii) The mycelium is made up of well-developed, profusely branched and septate hypha that
possess multinucleate cells and simple pore septa.
(iii) The hyphae may be inter- or intracellular, and their cell wall chiefly contains chitin-glucan.
(iv) Deuteromycetes reproduce only asexually. The asexual reproduction may take place by
hyphal fragments, budding (common in Blastomycetes), arthrospores (flat-ended asexual spores
formed by the breaking up of cells from the hypha), chlamydospores (thick-walled modified cells
functioning as resting spores), or most commonly by conidia or conidiospores (nonmotile spores
formed externally on the surface of hyphae or on specialized hyphal branches called
conidiophores).

3. (v) The cell of conidiophore that produces conidia is called conidiogenous cell and the
conidia may be produced either at the tip or side of the conidiogenous cell either singly or
in chains.
(vi) The conidiophores are either frees from one another (mononematous) or they may be
aggregated to form specialized structures such as synnemata and sporodochia.
In large number of Deuteromycetes, the conidiophores are formed in more specialized
and organized fruiting layers present within the specialized fruiting bodies called
conidiomata (sing. Conidioma; formerly called conidiocarps). The conidiomata may be
acervulus or pycnidium.
(vii) Sexual reproduction lacks, but a parasexual cycle or parasexuality generally operates
in their life to fulfil the requirements of sexuality.

4. CONIDIA AND ITS DEVELOPMENT
● Condia are exogenously produced spores
● They are non motile and are borne in externally or vertically growing
hyphae called conidiophores
● Conidiophores are simple or branched,bearing single or chain of conidia
● Ellis (1971) has recognised two type of conidial development:
1)Blastic
2)Thallic

5. BLASTIC
Marked enlargement of the recognisable conidial initial takes place before it is delimited
by a septum.
It may of two tpe:
HOLOBLASTIC
In the formation of conidia both the inner and outer walls of the conidia forming
cell of the conidiophores take place.
Eg;Cladosporium
ENTEROBLASTIC
Only the inner wall of the conidigenous cells takes part in the formation of condia
Eg;Helminthosporium

6. THALLIC
In this type of conidial development there is no enlargement of conidial initials,or
when such development does occur,it takes place after the initial has been delimited
by a septum or septa
Eg; Geotrichum candidum

7. TYPES OF CONIDIA ON FREE CONIDIOPHORE
2 type
THALLOSPORES
These are asexual spores formed by transformation of existing cells or thallus,the spores
are set free by decaying of thallus
Eg; Arthrospores & Chlamydospores
CONIDIOSPORES
Spores formed singly or in chains on conidiophores

8. ASEXUAL FRUCTIFICATION
SYNNEMA
Branched or unbranched conidiophore arise very close to each other and often united to form dense
fascicles.
Also called as Corenium
Towards the upper end the conidiphores become diverged and free and freevand forms conidia

9. SPORODOCHIUM
● Hemispherical or barrel shaped
● Consist of two part; upper and lower
● The lower part is a cushioned stroma like mass of hyphae,it breaks through th
host tissue,from the exposed upper surface arise the conidipphore which bear
condia at their tip.

10. Pycnidium
It is a flask shaped structure,the cavity of the flask is lined by a sterile
pseudoparenchymatous tissue comprising its wall.it is called pycnidial wall.the fertile
layer lies in the cavity ,the wall and the fertile layer is called pycnidium.the fertile layer
consist of very short conidiophores are called pycniospores.

11. ACERVULUS
It is a saucer shaped structure consisting of stromatic mass by hyphae and a fertile
layer of conidiophores

13. CLASS HYPHOMYCETES
● Hyphomycetes are asexual reproductive structures produced directly on their
substrate without any kind of enclosing tissues.
● The most common function of hyphomycetes is reproduction and dispersal,
although in some species the conidia may act as gametes or "spermatia" that
can fertilize an incipient dikaryon. • Hyphomycetes come in a staggering
variety of forms,
● This immense diversity reflects the role these forms play in the dispersal of the
fungus producing them.
● Each species grows in a particular habitat.

14. ● When the nutrients in this habitat are exhausted the fungus must ensure
that its offspring find their way to a similar source of nutrition.
● Getting their conidia to this new place, often a very small target, requires
precise dispersal mechanisms.
● Dispersal mechanisms includes:
-Air dispersal
-Water dispersal
-Dispersal by insects and small other animals.
● The class hphomycetes is classified into 4 orders based on the presence or
absence of conidia and degree of the aggregation of the conidiophores into
specialized structures called synnetama.
● Orders:
● Hyphomycetales
● Stilbellables
● Tuberculariales
● Agonomycetales

15. CLASS COELOMYCETES
● Coelomycetes are asexual Dikarya that produce their conidia inside some kind of
enclosing structure.
● The fungal hyphae germinate from conidia and form an aggregated mass until they
form a fertile layer of densely packed conidiophores.
● Conidiophores are simple or branched hyphae that develop specialized cells
(conidiogenous) from which asexual conidia are produced. It is this mass of
hyphae that create the fruiting structure known as a conidiomata,
● If this structure completely surrounds the conidia it is called a pycnidium; if the
conidia are borne in a more open structure with a wall only around the lower part it
is an acervulus.
● The pycnidium is very light coloured where it is sunken in the host tissues but dark
on top.
● This is a common phenomenon among pycnidial fungi.
● Most pycnidia release their spores in a wet mass that is extruded out through the
apical pore (ostiole). These often collect in large amounts and are either
transported away by insects or will flow along with rain water

16. ● Pycnidia resemble the fruiting structures of ascomycetes
called ascomata
● The second main type of conidomata are acervuli.
● Like pycnidia, acervuli also produce a mat of closely packed
conidiophores but instead grow in a raised mass.
● Unlike pycnidia, acervuli are typically open and cup-shaped
and the opening by which conidia are released is much
larger than that of a pycnidium.
● More commonly these fungi grow on living and dead plants.
● Some pycnidia and acervuli can be highly complex and be
composed of several cavities.
● Orders:
Melanconiales (producing spores in acervuli)
Sphaeropsidales (producing spores in pycnidia)
Pycnothyriales (produces pycnothyrial conidiomata.)

17. CLASS BLASTOMYCETES
● Members of this form-class are characterized by yeast-like cells which propagate by
budding.
● A pseudomycelium may or may not be formed.
● True mycelium is either lacking or is not well developed.
● Most of the members are saprobes occuring on flowers,wood, leaves, and barks.
● Some of them occur on fresh and sea water.
● Some associated with the plant disease like powdery mildews, rusts and smuts.
● Blastomycetes are also recognized pathogens in medicine.
● Both Candida, causing candidiasis or candidosis, and
Cryptococcus, causing cryptococcosis, are opportunistic pathogens that cause
systemic infections only in individuals with lowered resistance.
● Blastomyces dermatitidis is the causal agent of blastomycosisj an invasive and often
serious fungal infection found occasionally in humans and other animals in regions
where the fungus is endemic.
● The causal organism is a fungus living in soil and wet, decaying wood, often in an
area close to a waterway such as a lake, river or stream.