The document provides an overview of Chytridiomycotina and Zygomycotina, including their characteristics, ecology, reproduction, and life cycle patterns. It highlights the saprophytic and pathogenic nature of these fungi, their forms of reproduction, and their ecological importance, particularly in soil and plant interactions. The study emphasizes the evolutionary significance of Zygomycota in the development of higher fungi.

1. MYCOLOGY
Welcome to :
Chytridiomycotina & zygomycotina:
Characteristics & Ecology
By
N.Sannigrahi, associate professor
Deptt. Of botany, nistarini college,
purulia (w.B) India

2. WART OF POTATO(SYNCHITRIUM SP.)

3. POTATO PLANT

4. CHYTRIDIOMYCOTINA & ZYGOMYCOTINA
 HABITAT
 Mostly found to grow in water, soil, wind, estuaries & sea,
 Saprophytic or biotrphic parasites of vascular plants like
Synchitrium endobioticumm on potato and Olpidium brassicae
in the roots of mustard
 Some are pathogen to mosquito larvae
 THALLUS
 Unicellular without mycelium with branching extension called
rhizomycelium
 Holocarpic
 Either monocentric or polycentric
 Coenocytes with many nuclei

5. REPRODUCTION
 ASEXUAL REPRODUCTION
 Zoospores produced in zoosporangium, spherical or pear
shaped like structure
 The whole cell may develop to the zoosporangium or in
eucarpic, a part of the thallus may develop into zoosporangium
 Sporangium is full of protoplasm and nuclei
 Zoospores uninucleate with single posterior whiplash flagellum
 Zoosporangium bears one or more discharge tubes either by
breakage of the tip or by papillae
 Zoospores generally develop a cyst around it , germination
either by monopolar or bipolar.

6. ASEXUAL REPRODUCTION

7. SEXUAL REPRODUCTION
 Sexual reproduction takes place mostly either planogametic
copulation where conjugation takes place between isogametes,
 Two morphologically similar but physiologically dissimilar
gametes unite in water- gametogamy
 Oogamy very often takes place between much larger non-
flagellate globose egg with active motile gamete
 Somatogamy may occur fusion of undifferentiated hyphae
(Chytrimyces hyalinus)
 Nuclear fusion leads the formation of diploid zygote, resting
body continues to enlarge and develops a thick wall,
 Diploid resting spore , after a period of maturation acts as
prosporangium and then thin walled meiospores develop, gives
rise to the thallus after germination

8. LIFE CYCLE PATTERN

9. ZYGOMYCOTINA
 A true fungi having non-motile aflagellate spores
in asexual reproduction and zygospores after
fusion of gametes in sexual reproduction.
 The most common are Mucor, Rhizopus,
Blakeslea, Mortierella etc.
 It has been divided into two classes-Zygomycetes
& Trichomycetes. Zygomycetes contain 870
species under 10 orders while Trichomycetes
have 218 species under 3 orders. Mucorale is is
the core order and Zygomycetes is the true class
in this regards. The Subdivision is a unique one
as it is the most turning point as far as the origin
and development is concerned.

10. ECOLOGY & OCCURENCE
 Abundant in soil and mostly saprophytic in nature,
coprophilous grow and develop on the dung of
herbivores.
 Early colonizers in fungal succession
 Sometimes act as pathogens and cause rot of sweet
potatoes, fruits like apples, tomatoes, strawberries etc
and cause fruit spoilage
 Rhizopus and Mucor cause human lesions
 Mucor on animals cause a disease called Mucormycosis
 Rhizopus is called bread mould
 Members of Glomales form mutuality association with
plant as mycorrhizal association
 Commensalism found with arthropods inhibiting on the
gut of the organism.

11. CHARACTERISTICS
 Mycelia thallus are coarse, coenocytes with dense
branching with tapering to fine points,
 Mostly aseptate and eucarpic,
 Rhizoids are borne at the base of the
sporangiophores. The aerial hyphae touches the
substratum, bear rhizoids and sporangiophores
 Aerial hyphae are called stolen that run parallel
to the substratum,
 Mucor grows like yeast in aerobic culture but
reverts filamentous in presence of oxygen,
 Cell wall complex with chitin, micro fibrils and
other polysaccharides in the cell like proteins,
pyrimidines etc,
 Nuclei irregular in shape and divide by
constriction.

12. VEGETATIVE STRUCTURE WITH REPRODUCTION

13. REPRODUCTION
 Vegetative by means of usual fragmentation of
hyphae and each fragment grow into new thallus.
 ASEXUAL
 The asexual spores called sporangiospores borne on
sporangia.
 The number of sporangiospores may be numerous or
reduced in number called sporangioa.
 Spores are aplanospores i.e. non-motile and borne on
the globosely sporangia at the tip of the
sporangiophore.
 The sporangium have distinct central columella over
arched by the spores and uninucleate in nature.
 Mostly the sporangial wall ruptures and dark,
elliptical spores discharge and geminate upon a
substratum.
 Very often thick walled chlamydospores may form
during the asexual method.

14. SEXUAL REPRODUCTION
 The process of conjugation and isogamous nature
is exercised with a predominant haploid phase.
 Conjugation occurs between two identical
coenogametangia to form zygote and then
becomes zygospores,
 Both homothallic and heterothallic. In
heterothallic, two compatible strains rarely differ
to each other morphologically or physiologically
and may be labeled as (+) and (–) (Blakeslee,
1906).
 Two compatible strains differ in mating types
 A progamatangia develop followed by the
formation of Zygophores. A hormone trisporic
acid induces the process.

15. ASEXUAL METHOD

16. SEXUAL METHOD
 The hyphal branch-like + & - strains contact to
each other, progametangia bears suspensor and
gametangium fuse together. The gametangia
called coenogametangia having mass of
undifferentiated mass of uninucleate protoplast,
 The separating wall dissolves and the mixing of
the protoplasm forms zygote , then swells and
develop a dark warty outer layer to become
zygospore
 The zygospores matures, breaks up gametangial
wall, zygospores germinate to form germ
sporangia having numerous spores inside it.
 The spores germinate and gives rise to the new
mycelia as asexual method told earlier.

17. SEXUAL METHOD

18. LIFE CYCLE PATTERN

19. CONCLUSION
 As per evolution is concerned, Zygomycota , in
turn probably has given rise to Ascomycota And
Basidiomycota in the passage of time. It is
believed that Zymycota emerged between 600-
1400 million years and it makes the passage of
the evolution of the higher fungi in due course.
Thus, Zygomycota is taxonomically evolutionary
and ecologically important group of fungi.

20. THANKS A LOT FOR YOUR JOURNEY
 Acknowledgement:
 Introduction to Mycology & Phytopathlogy by Mishra & Dash
 A Text Book of Botany by Maiti, Bhattacharya & Ghosh
 An introduction to Fungi- Vasistha
 Many contents from WebPages
 Images from Google
 Declaration:
 This presentation has been prepared for the academic interest virtually for UG
students of India & abroad especially in pandemic period without any financial
interest.