Ascomycota

General characters and small introduction has been given, outline of important fungi that comes under Ascomycota has been described

1. ASCOMYCOTA
N.H. SHANKAR REDDY
2
nd
Ph.D. Plant Pathology
Annamalai University

2. General characters
•Otherwisecalledassacfungi
•Cellwallismadeupofchitin+glucan
•Myceliumiswelldevelopedandseptate
•Crozierformationiscommonfeature,butclampconnectionandDoliporesepta
isabsent
•Thesporesareproducedinsideasmallsaclikestructurecalledascus.The
sporesproducedbytheascusarecalledastheascospores.Theascuscontains8
ascospores(ascosporesareproducedendogenously/inside)
•Ascomycotafungihavebothsexualandasexuallifecycles
•Asexualreproductionbymeansoffragmentation,buddingandconidiogenesis
(formationofconidia)

3. •Malegametangium–antheridium,
•femalegametangium-ascogonium
•Asexualspores–conida
•Sexualspores–ascospores
•Therearethreetypesofascocarps:i.Cleistothecium
ii.Perithecium
iii.Apothecium
iv.Ascostroma

4. Asci
•Ascimay be spherical to elongated with cylindrical, ovoid, or globose
forms.
•Each ascicontains 8 ascospores

5. Different types of fruiting bodies (ascoma/ ascocarp/
ascomata) produceedby ascomycota
1.Cleistothecium–Itisaglobular,
completelyclosedascocarpwithno
specialopeningtotheouside,where
theasciarepackedinside.
2.Apothecium–Itisasaucershaped
completelyopenedascocarp,whereasci
areproducedisanopenascocarp.The
asciarefreelyexposedatmaturity.
Eg–Pezizales,Heliotiales

6. 3.Perithecium–Itisaflaskshaped,
partiallyopenedascocarp(moreorless
closed)butatmaturityisprovidedwitha
smallporeattheopeningcalledostiole
fromwhereascosporesarereleased.
•Eg–SphaerialesandHypocreales
4.Nackedasci–Asciareproducedonthe
surface

8. Crozier formation/ Ascsformation
•Notethecrozierhookproducedbytheascogenoushypha,
whichallowsthetwohaploid(N)nucleitodivideandmigrate
simultaneouslytotheprotoascus,wheretheywillundergo
karyogamy(2N),whichisimmediatelyfollowsbymeiosis(4x
N)andgenerallyalsobyamitosis(>8xN)