This document summarizes key characteristics of the phylum Ascomycota. It describes their septate mycelium, absence of flagella, and formation of sexual ascospores and asexual conidia. Ascomycetes reproduce sexually through the union of nuclei in ascogonium and antheridium, without fertilization tubes. Their fruiting bodies include cleistothecia, perithecia, apothecia, and ascostroma, which contain ascospores in sac-like asci. Asexual reproduction occurs via conidia, budding or fragmentation. The largest phylum, Ascomycota, includes the subphyla Saccharomycotina (yeasts), Taphrin

1. Phylum: Ascomycota ( Ascus forming fungi)
Largest phylum having about 75% of all know fungi
- Septate mycelium
- Absence of flagellated structures
- Formation of conidia
- Sexual spores ascospores
- Somatic structure:
- Well developed septate and profusely branched mycelium
- Cell wall made up of chitin
- Somatic tissues like sclerotia, stroma and mycelial strands
- Sclerotia – Aggregation of modified somatic hyphae which serve as resting
bodies.
- Stromata- compact somatic structures which bear spores or the
fructifications
- Mycelial strands: Rhizomorphs

2. Reproduction:
Asexual Reproduction:
Conidia, budding, fragmentation, chlamydospores, fission
Conidiophores- pycnidia, acervular ,sporodochium
Sexual Reproduction Union of two compatible nuclei; These nuclei are brought close
To each other by means of the plasmogamy. In most of ascomycotina delay between
plasmogamy and Karyogamy.
Sex organs:
Female sex organs differ morphologically ascogonium
Male sex organs is antheridium and is club shaped
No fertilization tube is ever formed in ascomycotina

3. Fruiting bodies:
During the development of asci, the surrounding monokaryotic hyphae form
A thick protective wall, excipulum, around the developing asci.
The hyphal tissues that form the excipulum comprise of prosenchymatous or
pseudoparenchymatous tissues. The wall and the asci are jointly called ascoma.
Ascomata protect the asci and also regulate the release of the ascospores.
Ascomata are of four morphological types.
Cleistothecium: Which is completely closed and usually globular.
Contain asci inside and irregularly arranged.
Perithecium: which is ostiolate and globular or more commonly flask shaped
Apothecium: Which is cup or saucer shaped, bearing exposed hymenium.
Ascostroma: In which the asci are formed in preformed locules in stroma.

4. Perithecium

6. Development of ascus:
A. Direct ascus formation: In lower ascomycotina the zygote cell directly develops in
to an ascus. Karyogamy immediately occurs after plasmogamy. Karyogamy-
Diploid. Meiosis followed by Mitotic division
B. Indirect formation of ascus: In higher ascomycetes karyogamy doesn’t occur
immediately after plasmogamy.
C. 1. Formation of ascogenous hyphae
D. 2. Crozier formation: Tip of the ascogenous hyphae containing one of the
binucleate cell bends
E. 3. Karyogamy and Meiosis: Two nuclei of penultimate cell undergo karyogamy
F. To form a diploid zygote cell or ascus mother cells.
G. zygote nucleus undergoes meiototic division followed by mitotic division which
results in to eight haploid nuclei.
H. 4. Ascospore formation: eight daughter nuclei to form eight uninucleate haploid
I. Ascospores.

7. Crazier formation

8. Asci: Sac like structure wall of unitunicate ( thin single layer) or bitunicate
( two distinct wall)
Outer wall is known as ectoascus which is thick and ruptures transversely
Near the apex to permit the inner wall Endoascus to expand into a long cylindrical sac .
The endoascus has an pore through which the ascospores are successively discharged
Ascospores: Shape, size, colour and ornamentation of ascospores varies according
To the species ascospores arranged irregularly in the ascus single row ( uniseriate)
Double rows ( biserate)

9. Sterile structure:
1. Interascal pseudoparenchyma: compressed between developing asci
2. Paraphyses: Hyphae originating from the base of the cavity usually
Unbranched and not anastomosed
3. Pseudoparapysa: Hyphae originating above the level of the asci and
Growing downwards between the developing asci.
4. Paraphysoids: Hyphae streching and resembling pseudoparaphyses
5. Periphysoids: Short apical hyphae, originating above the level of the
Developing asci, growing down wards but not reaching the base of the
cavity.
6. Periphyses: Hyphae confined to the ostilar canal, unbranched and
not anastomosing.

10. Release of ascospores:
1. Closed ascomata are exposed for release of the ascospores only after the
Disintegration of the ascoma.
2. In Perithecia, the asci elongate until their tips reach the ostiole ( One at a time)
for discharge of the ascospores.
3. In some genera, expecially those having long-beaked perithecia, the asci get
Detached and ooze out of the pore in succession.
4. In other genera the ascus wall dissolves and the ascospores are released within
The cavity of perithecium from where they are released in a mass of slime.
Such ascospores are usually transmitted by insects.
5. In apothecia, the asci are oriented in a way which facilitates easy discharge of the
Ascospores with help of paraphyses.

11. Germination o ascospores:
In yeasts and some other genera the ascospores multiply by budding before
Germination. During germination the germ tubes emerge from a germ pore
Or germ slit and gives rise to the somatic hyphae.

12. Classification: Kirk et al., 2008 10 th edition of the dictionary of fungi
Phylum: Ascomycota
Sub Phylum: 1. Taphrinomycotina
2. Saccharomycotina (True yeast)
3. Pexizomycotina ( Filamentous) sporocarp and conidia are produce
1. Taphrinomycotina: Mycelial fungi, unicellular, yeast species, multiplying by fission
Dimorphic, partial mycelium and partial yeasts
Class: 1. Archaeorhizomycetes
2. Neolectomycetes
3. Pneumocystidomycetes
4. Schizosaccharomycetes
5.Taphrinomycetes G.Taphrinales F1. Protomycetaceae 2. Taphrinaceae.

13. G: Thaphrina ( Anamorph: Lalaria) 91 species- parasitic on higher plants and ferns
Dimorphic, forming mycelium and asci in the parasitic phase and yeast colonies of
Budding cells in the saprobic phase.
Taphrina deformans: peach leaf curl
T.pruni: plum disease of plum disease of plum fruit
T. epiphylla: Whitches broom of cherries.
Cause necrotic leaf spots, galls, whitches broom
Life cycle: The blastospores, formed by budding of ascospores, germinate on young
Peach leaves.

15. 2. Sub Phylum: Sacharomycotina ( Yeast, ascomycetous cells)
-Unicellular
-Mycelium absent or poorly developed
-Cell wall made up of B-1-3 glucans
-Direct development of asci from zygote
-absence of ascomata
Class: Saccharomycetes
O: Saccharomycetales- unicellular yeast 13 Family 75 genera
F: Ascoideaceae, cephaloascaceae, Diplodascaceae, Enodmycetaceae,
Ermotheciaceae, Lipomtycetaceae, Metschnikowiaceae, Phaffomycetaceae,
Pichiaceae, Saccharomycopsidaceae, Saccharomycopsidaceae, Trichomonascaceae
- Direct developmentof asci from the zygote
- Lack of mycelium and absence of ascomata
- The thallus is represented by single cells, pseudomycelium or freely developed
- Hyphae with septa. Septa have several minute pores.

16. F: Endomycetaceae: G. Ascoidea 4 species
A.rubescens- produces exudates of peach, hypae are made of uni or multinucleate cells
Conidia are produced singly at the hyphal tips. Oval asci bearing hat shaped ascospores
F: Saccharomycetaceae- Ascomycetous yeasts 28G, 159 species
- Mycelium absent
- Somatic cells proliferate by multiple budding
- Asci morphologically similar to the somatic cells and contain 1 to 4 globose ascospores
- Grow on sugary substrate like flower nectar, ripe fruits, milk, soil, animal extracts
- Plant parts.
- Ferment sugars under anaerobic conditions
- Asexual reproduction occurs by budding Asci develop directly from the zygote.
- G. Saccharomyces, 10 species. S.cerevisiae yeast of commerece or bakers
- And brewers yeast” because use in production of alcohol and co2
-
Conidia

17. Life cycle: haplo-diplobiontic ( both haploid and diploid phases
are equally extensive and important. The haploid cells of opposite mating types after
Fusion ( Plasmogamy and karyogamy) give rise to diploid cells. Diploid cells undergo
meiosis and forms four haploid nuclei around which four ascospores
Budding
Zygote

18. 3. Sub Phylum: Pesizomycotina ( crown group o ascomycetes, Filamentous,
Ascoma-forming fungi.
Class: 1. Arlloniomycetes- Ascoma opothecia, asci bitunicate
2. Dothideomycetes- Ascostroma, asci bitunicate
3. Erotiomycetes- Perthecial, cleistothecia, ascostroma, bitunicate, prototunicate
4. Geoglossomycetes: Apothecia, cleistothesia, inoperculate, prototunicate
5. Laboulbeniomycetes- Perithecia, prototunicate
6. Leotiomycetes – Apothecia, cleistothecia,
7. Orbiliomycetes- apothecia, operculate
8. Pexizomycetes- apothecia, operculate
9. Sordariomycetes- Perithecia, cleistothecium, inoperculata.

19. Class 2: Orbiliomycetes: apothecial ascoma, inoperculata asci
O: Orbiliales F: Orbiliaceae
G: Dactylella bembicoides- Nematode trapping fungi
Sudden swelling of ring cell
Class3:Pezizomycetes- apothecial ascoma, operculate asci
O: Pezizales F: Ascocolaceae G: Ascobolus A. crenulatus- coprophilus forming
Apothecia on dung of hervivore animals
Class4: Dothidomycetes- ascostroma, ascibitunicate
Sub class: Dothideomycetidae
O: 1. Capnodiales 2. Myringiales 3. Dothidiales
O Dothidiales: 58 family 711 genera 4774 species
Ascomata: apothecium, perithecium or cleistothecium, lysigenous cavities
Within the stromatic tissues. Asci, usually cylindrical, paraphysoids or
Pseudoparaphyses, Ascospore septate

20. conidia

21. apothecia
Ascospores two layered

22. F: 1. Mycospharellaceae: 13 plant parastic genera : perithecium asci ovoid to saccate and
Bitunicate, Ascospore septate
G: Mycospharella: 500 species.
M. Muscicola banana sigatoka leaf spot, M. arachidicola Tikka disease of groundnut
M. berkeleyii, M. tassiana
Asexual: Pycnidia, Acervulus or hyphomycetous M. typhae
Anamorph: Cercospora, Corcosporella, Cercosporidium, Pseudocercospora, Septoria
F2. Venturiaceae G: Venturia inequalis apple scab V.pyrina- pear scab
Spilocae pomi
Perithecioid pseudothecia, which are remain immersed in the host tissue and open to
The exterior through an erumpent ostile.

23. Mycosphaerella
Bitunicate ascus with
Two celled ascospores

24. Conidia
Upper bigger
Lower small

25. O: Capnodiales: Meliolaes- Meliola- sooty mold
F: Meliolaceae 24 genera 1600 species
Capnodium
Superficial hyphae are dark coloured and attached on the host with hyphopodia,
Stiff erect bristles called setae, spherical, thin walled cleistothecia, asci unitunicate
Thin walled, ascospores dark brown coloured, thick walled, septate ( 2-5celled), unitunicate
Coloured ascospores

26. Class: Eurotiomycetes: Penicillium , Aspergillus, Chaetomium
Sub Class: 1. Chaetothyriomycetidae ( 3 Order)
2. Eurotiomycetidae ( 3 orders)
Sub class: Chaetothyriomycetidae
O. 1. Sordariales F. Chaetominaceae G. Chaetomium,
F. Sordariaceae G. Sordaria and Neurospora
Cheatomium: 80 spp. Cellulose degrading fungus, growing on paper, fabrics
And other cellulose-rich materials
Thermophilic C.thermophile, C.globosum- cellulose degrading
Perithecium, which has a long beak and covered with hairs.
Curly at top and straight at the base, asci are stalked, club shaped, cylindrical or oval
And produced in a basal tuft. Ascospores released passively oozing mass of mucilage.
Conidia are not produced

28. F: Sordariaceae: Sordaria, Neurospora crassa
Neurospora sitophila- red bread mold- infection to bread pink growth on bread
Imperfect: Monilia
O: Ophiostomatales F: Ophiostomataceae 5 genera
G: Ophiostoma ulmi dutch elm disease Anamorph: Graphium
Perithecia which have a long neck and ostiler setae asci are small, formed in chains
Sub Class 2: Hypocreomycetidae
O: Hyphocreales F: clavicipitaceae G. Claviceps purpurea - ergot of bajra,
C. sorghi- ergot of sorghum
Filiform ascospore- Apex of the ascus, is slightly thickened and contains a large
Chitinous body which can be stained with cotton blue
Conidia honey dew like substances

29. Claviceps
Ascus chitinous cap

30. Neurospora
Brown to black
ridges or
striations

31. Class: 5: Leotiomycetes- apothecia, cleistothecia, inoperculata, prototunicate
O: 1. Cythariales 2. Erysiphales 3. Helotiales
O: Cythariales: F: Cythariaceae G. Cytharia 10 species
Parasitic on Nothofagus formation of galls. Brightly coloured stomata
Each consisting of 200 embedded apothecia, appear on the stems of infected plants.
Apothecia: with numberous filamentous paraphyses asci are cylindrical 8spores

32. Order: 2 Erysiphales obligate parasite F: Erysiphaceae 21 genera 437 species
No paraphyses, asci bitunicate, cleistothecia with external appendages
Asci bitunicate, Haustoria- globose or digitate
Genera classification
1. type of the appendages on the cleistothecia
2. Nature of mycelium Ectophytic/endophytic
3. Number of asci

33. Powdery mildew genera
Oidium
Oidiopsis
Clestothecium

34. Erysiphe Phyllactinia
Uncinulla
Several ascus
Microsphaera- Dichotomously branched
Coiled appendages
Bulbus base
Myceloid appendages

35. Sphaerotheca Podosphera
Single ascus

36. Order 3: Helotiales 10F. Sclerotiniaceae 47 genera 248 species
F: Sclerotiniaceae : Club shaped apothecia which are yellowich
long stalked arising from sclerotia or stroma
Sclerotinia sclerotiorum : crown rot, point rot, celerah drop of lettuce
Monilinia- apothecia on mummified fruit M. fructigena, M. fructicola – brown rot of stone fruit
Sclerotinia- apothecia arise from seed like sclerotium

37. Sclerotinia
Apothecia

38. Class: Eurotiomycetes
Sub class: Eurotiomycetidae
O: Eurotiales
F: Trichomaceae
G: Aspergillus: A. oryzae- alchol from rice starch, A. niger- citric acid
A. fumigatus, A. flavus, A.nidulans- cause otomycosis human
B. A. fumigatus, A. flavus- infect lungs
C. A. niger, A. flavus – Groundnut collar rot
Penicillium ( Blue mould or green mould 250 species
Found in air , soil. Grow saprobic and grow on decaying vegetable, fruit, jellies and
Other food stuffs
P. italicum- Blue mould citrus, P. digitatum- green mould on citrus
P. patulum- alcohol, P. expansum-decay of apple,
P. chrysogenum, P. notatum,
P. comemberti-cheese

39. Aspergillus
Ascospores

40. Penicillium
Ascocarp
Ascospores

41. Order: Microascales
G> Ceratocystis
C. fimbriata- Hat shape ascospores
C.ulmi- oval shape ascospores
C.Piliforum
C.Inor
C.Piceae
C.Frgacearum
C.Paradoxa – sett rot of sugarcane

42. Ophiostoma

44. Ainsworth 1973Sub division Deuteromycotina
Class:
1. Blastomycetes- Yeast cells, pseudomycelium, True mycelium but not well developed
2. Hyphomycetes- sterile hyphae bearing conidia, conidia are not borne in Pycniida or
Acervuli fruiting bodies
3. Coelomycetes- spores are formed in pycnidia and acervulus, conidia are specialized
bearing structure, sporodochia, synnemata
Class: Blastomycetes S.C: Blastomycetidae- soma consisting of yeast cells with or
without pseudomycelium, True mycelium present but not well developed.
O: 1. Sporobolomycetales: produce ballistospores G: Bullea, Sporobolomyces, Itersonilia
and Tilltiopsis -- Imperfect stage of Basidiomycota
2. Cryptococcales- budding, no ballistospores- Imperfect stages of ascomycotina and
Basidiomycotina G: Rhodotorula, cryptocococus, candida, Torulopsis
Trichosporon cutaneum
Trichosporon beigelli- white piedra diseases of hairs of the scalp
Pityrosporum ovale- Dendruff
Pityrosporum arbiculara- skin infection of human

45. Class : Hyphommcetes: SC: Hyphomycetidae O; Moniliales
F: Moniliaceae- hyaline hyphae, hyaline conidiophores
Aspergillus, penicillium, acroorium, Neurospora, Monilina, Botryotinia,
2. Dematiaceae- Coloured mycelium with coloured conidia and conidiophore
Alternaria, curvularia, Drechslera, Helminthosporium ,cercospora
3. Tuberculariaceae- Sporodochium- fusarium, Tubercularia, Volutella
4. Stillbellacea- Synnemata, Graphium, Ceratocystis

46. Coelomycetes: SC: Coelomycetidae: conidia in pycnidia or acervuli
Pycnidia- O:1 Sphaeropsidales: pycnidia are superficial or immeresed, globose,
elongate or cup like, unilocular or multilocular, light or dark in colour, produce
separately or aggregated
F: 1. Sphaeripsidaceae- pycnidia dark coloured, globose, hard
2. Nectrioidaceae- Similar to sphariopsidaceae but light coloured, soft or waxy
3. Leptostomataceae- Pycnidia, shield, shaped or elongate, flattened
4. Excipipulaceae- Pycnidia more or less cup or saucer shaped
Phyllosticta, phoma macrophoma, dendrophoma and phomopsis
O: 2. Melanconiales- Acervuli: Collectotricum, Melanconium, Marssonina,
Entomosporium, Pestalotia, septoria, ascochyta, chaetomella
O: 3. Agonomycetales: Mycelia sterilia- Reproduction by fragmentation of the
hyphae Rhizoctonia, sclerotium

47. Types of Phialides:
1. Cladorrhinus
2. Penicillium
3. Chalara
4. Fusarium
5. Philophore
Penicillium
Aspergillus

48. Chalara
Cladorrhinus

49. Septation and shape of matured conidia
1. Amerosporae- single celled-Hyaline conidia- Hylosporae, Pigmented-Phaerosporae
2. Didymosporae-spores 2 celled Hyaline-Hyalodidymae Pigmented- Phaerodidymae
3. Phragmosporae- more than 2 celled- Hyaline-Hyalophragmae, Pigement-Phaeophragmae
4. Dictyosporae- muriform- Hyaline- Hyalodictyae, Pigment-Phargmodictyae
5. Staurosporae ( star shaped
6. Scoleosporae ( fillifom)
7. Helicosporae ( Helical)

51. Conidia and conidiaphore development
I Blastic: conidial initial takes place before it is delimited by a septum
1, Holoblastic: In the formation of conidia both the inner and outer walls of
the conidia forming cell of the conidiophores take part. Cladosporium
2. Enteroblastic: Only the inner wall of the conidiogenou cell takes part in the
Formation of conidia
a. Tretic: The conidium develops when the inner wall potrudes through a
channelIe the outer wall Helminthosporium
b. Phialitic: Conidi a development takes place form a specilized conidiogenous
cells Penicillium, aspergillus
c. II. Thallic: Type of conidial development there is no enlargement of conidial
initialy or such development does occur, it takes place after the initial has
been delimited by a sepum or septa Geotrichum

52. Phialidic
Tretic

53. Types of conidia on free conidiophore
A: Thallospores: Asexual spores formed by the transformation of existing cells of
the thallus
1. Arthrospores: Arthrospores arise by close septation of the distal part of
hypha, the septa being formed in basipetal succession.
2. Chlamydospores; These are formed from a solitary or meighbouring
intercalary cells of a hypha, which round off, enlarge of a hypha and develop a
thickened spores.

54. B. Conidiospores: These are asexual spores formed singly or in chains on a
conidiophore
1. Blastospores: Blastospores or bud spore is formed by budding of somatic
cells of a hypha or conidiophore or by budding the cells of other types of
spores
2. Porospores: Modified blastospores and are produced as a bud extruded
through a distinct pore in the wall of conidiophore
3. Aleuriospores: These spores are formed by the apex of the conidiophore
becoming inflated and delimited by a septum at an early stage Oidium
4. Phialospores: These are conidia which are abstricted in basipetal sequence
from phialides. Aspergillus
Aleuriospores

55. c. Aggregation of conidiophores or Asexual fructications
Synnema: Unbranched conidiophores arise very close to each other
and are often united along a greater part of their length to rurn
dense fascicles
Sporodochium- cushion stroma like mass of hyphae
Pycnidium: Flask shaped fruiting bodies
Acervulus: Saucer shaped structure consisting of stromatic mass of hyphae