Sub Division of Eumycota

1. SUBMITTED BY
Vivek kumar
MSc MICROBIOLOGY
Bangalore University

2.  It is a zoosporic fungi
 Sub division of Divison Eumycota
 Plasmodium or pseudo plasmodium absent.
 Assimilative phase typically filamentous.

4.  True fungi.
 Approx.75000 known species.
 Thalli do not posses plasmodi or
pseudoplasmodia.
 Unicellular or filamentous.
 Definite cell wall
 Growth of hyphae is apical.

5.  Commonly known as “zoosporic fungi”
 Adapted mostly in aquatic habitat.
 Most of them are filamentous & have
coenocytic mycelium.However unicellular
form are present, and some genera show the
pseudosepta(falsecrosswall)formation.
 Centric nuclear division.their centrioles
remains functional during nuclear division.
 Live either saprophytes or parasites.
 Sexual reproduction by oospore formation.

6. Zoospore are flagellated fungi reproduce
asexually by means of flagellated spore
produced in zoosporangium.
 Three types of zoospore
1. Laterally biflagellate
2. Posteriorly uniflagellate
3. Anteriorly uniflagellate

7.  By AINSWORTH,1973
 3 CLASSES
 On the basis of flagellation of zoospore
1. Chitridiomycetes
2. Hypochitridiomycetes
3. Oomycetes

8.  The vegetative body is unicellular or chain of
cells attached with substratum by rhizoids.
 Cellwall is made up of chitin &glucans.
 Plant body is normally haploid.Except
Allowmycetes
 Produces posteriorly uniflagellate zoospore.

9. ASEXUAL
REPRODUCTION
By zoospore produced
in zoosporangium.
Zoospore are
uniflagellate,flagellum
whip lash
type&posteriorly placed
SEXUAL
REPRODUTION
By pianogametes
developed in
gametangia.fused to
form zygote
meisios----forms new
haploid thallus

11.  Halocarpic-primitive forms may consist of a
unicellular thallus without specialized
vegetative parts which converted to
reproductive organ. Eg; Olpidium
 Eucarpic-Reproductive organs arise from only
a position of the thallus.
 Eucarpic monocentric –Rhizoidal system
bears only a single reproductive structure.
 Polycentric-Rhizoidal system bears more than
one reproductive structure.

12. 1. Chitridiales -True mycelium lacking rhizoids
or rhizomycelium present in some species
2. Blastocladiales-sexual reproduction
present.,zoospores with nuclear cap;thick
walled ,resistant sporangia formed
3. Monoblepharidales-Sexual reproduction ,no
resistant sporangia formed.
4. Spizellomycetales-Mainly in soil.
5. Neocalimasticales- occur in rumen

13.  Examples of chitridiomycetes…..
 1.Synchytriun endobioticum: cause wart
disease of potato.
 2.Olpidium brassicae:cause wart diseases in
roots of crucifers.
 3.Urophlyctis alfalfae:causes crown wart of
alfalfa(medicago)
 4.Physoderma maydis:causes brown spot of
maize.

14. Wart disease
of potato
Brown
spot of
maize
Crown wart
disease of
alfalfa

15.  Aquatic fresh water or marine fungi
 Zoospore are anteriorly uniflagellate
 Thallus is halocarpic or
eucarpic,&monocentric or polycentric
 Vegetative system is rhizoidal or hypha like
with intercalary swellings.

17.  Cellwall contains chitin or chitin with
cellulose
 The sporangia are inoperculate
 The zoospore are either completely
differentiated in the sporangium.
 & Zoospore differentiate outside the
sporangium.
 Similar to morphological structure of
chytridiomycetes but differ from them in the
structure and anterior flagellation of the
zoospore.

18. 1. Hyphochytriales or anisochytridiales
 Based on the organization ,morphology
&development of the thallus
 3 families
1. Anisolpidiaceae
2. Rhizidiomycetaceae
3. Hyphochytriaceae

19.  On the basis of differences in molecular weights
of rhibosamal RNA Lovett &Haselby(1971)found
that anisochytridse could not be placed in any
other major class of fungi.
 Bartnicky Garcia(1970) also placed the
anisochytrids out side the main phylogenitic line
of fungi.But nearer the oomycetes.
 Le John (1972)on the basis of regulation of
glutamic dehydrogenase activity proposed that
anisochitrids are predessors of both the
Chytridiomycetes&Oomycetes.

20.  The hyphochitridiomycetes differ from the
Chytridiomycetes on the basis of the
pathways of lysine synthesis,the nature of
the flagella as well as the cellwall composition
(cellulose chitin).
 In hyphochytridiomycetes diaminopimelic
pathway of lysine synthesis occurs, where as
in the chytridiomycetes it is aminoadipic.
 Also difference in the position of the
flagellum on the planospores.
 This justify place in a separate class
Hyphochytriomycetes.

21.  Vegetative body is filamentous and
coenocytic except the unicellular
Lagenidiaies.
 Halocarpic or eucarpic.
 Cellwall contains cellulose and glucans
&chitin is absent

23. Asexual reproduction
 By biflagellate heterokont&anisokont
zoospore that are produced in zoosporangia.
 Zoosporangia-modified hyphae that are
usually terminal delimited by a septum.
 Zoospores are diploid formed by mitosis.
 Anteriorly directed flagellum is tinsel type
&posteriorly directed is whiplash type.
 Depending on genera two types of
zoospores are formed

24.  Two types of zoospores are there formed in
the lifecycle
1. Primary zoospore-First formed pip
shaped&the flagella are located anteriorly ,
which is released from the zoosporangium
,encyst &germinates to form the secondary
zoospore.
2. Secondary zoospore-The secondary
zoospore which is reniform or bean shaped
and laterally flagellated.
 Zoosporangium and zoospores are the
major dispersal agents for most species.

25.  Sexual reproduction is heterogamous
(oogamous) by oogonia(female) and
antheridia(male)
 Female gamete(oosphere)produced by
oogonium.
 Depending on taxa there may be one to many
oospheres per oogonium. male gamate is
produced by antheridium and transferred to
the oogonium by gametangial contact and
migration of male nuclei into oogonia and
fertilize oosphers Homothalic- self fertile or
heterothalic-opposite mating type required
for sexual reproduction.

26.  A swimming sperm is absent in the
oomycetes.
 This type of sexual reproduction is referred
to as gametangial copulation.
 In antheridia &oogonia meiosis take place.
 The eggs and sperms are products of meiosis
and the only parts of the lifecycle that are
haploid.
 Diploid zygote develops into thick walled
resistant oospore that germinates and give
rise to vegetaive diploid hyphae that
reproduce asexually by production of
zoospores.

28.  Four orders
1. Lagenidiales(Salilagenidials)
2. Leptomitales
3. Saproleginales
4. Peronosporales-This order has some of the
most well known pathogens cause diseases
to many crop plants. It divides into 3
families;
1.Pythiaceae-pithium,phytophthora
2.Peronosporaceae-plasmopara
3.Albuginaceae-Albugo

29.  The most economocally important group of
oomycetes is the peronosporales.
 It contain the late blight of potato fungus
Phytophthora infestans and relatives such as
peronospora ,Bremia, Plasmopara and others
that cause ‘downy mildews’ ,the ‘damping
off’ fungi,pythium spp. And the white rust
fungi, albugo spp.

30.  AN INTRODUCTION TO MYCOLOGY:
Alexopoulos, Mims,Blackwell
 AN INTRODUCTION TO MYCOLOGY
R.S Mehrotra,KR Aneja