Glomeromycota, Blastocladomycota, mycelium, spores, sexual structures, Antheridin,parasin, trisporic acid, phototropic fungi

1. WELCOME

2. Classification of Blastocladiomycota and Zygomycota (kirk et al.,
2008)
Harish J
PAMB1087
Department of Plant Pathology
UNIVERSITY OF AGRICULTURAL SCIENCES,GKVK,
BANGALORE

3. Blastocladiomycota

4. General Characteristics
 Members occur saprophytically in water or
plant debris or soil
 The thallus is eucarpic or holocarpic, rhizoidal
system is common
 Posteriorly uniflagellate zoospores are
produced as asexual spore
 Sexual reproduction: isogamous or
anisogamous
 Alternation of generation is common.
 Presence of gamma particles
 A prominent nuclear cap is found in zoospores
and planogametes.
Zoospores

5. Blastocladiomycota
Blastocladiomycetes
Blastocladiomycetales
Blastocladiaceae Catenariaceae Coelomomycetaceae Physodermataceae Sorochytriaceae
 Allomyces
 Blastocladia
 Blastocladiella
 Blastocladiopsisa
 Microallomyces
• Catenaria
• Catenophlyctis
• Coelomomyces
• Coelomycidium
• Callimastix
• Physoderma
• Urophlyctis
 Sorochytrium
Domain - Eukarya
Kingdom - Fungi
Phylum
Class
Order
Family
Genus
(Kirk et al., 2008)

6. Genus: Allomyces
• Allomyces was first discovered in India in 1911 by E.J. Butler, they
exist in soil and water as saprobes.
• Septa are absent except at the bases of reproductive organs and older
hyphae.
• The female gametangium produce a pheromone called sirenin which
attracts the male gametes.
• The female gametes are sluggish swimmers and tend to remain near
gametangium following release allowing male gametes to find female
gametes for fertilization.
• Male gametes also produce female attracting pheromone called
parisin.

7. Allomyces macrogynus - Alternation of generations

8. Genus: Physoderma
• All members of this genus are obligate parasites of vascular plants
• Magnus, in 1901, used characteristics of the resting spore and host
plant reaction to distinguish between Physoderma and Urophlyctis, he
claimed that resting spores from Physoderma were globose and
ellipsoidal, and those from Urophlyctis were flattened on one side.
• Physoderma species cause discoloration and slight malformation,
while Urophlycits cause significant malformation and hypertrophy.

9. Brown spot of maize - Physoderma maidis
Crown wart of Alfalfa - Physoderma alfalfae Sugarbeet crown wart - Urophlyctis leproides

10. Genus: Coelomomyces
• Coelomomyces produce coenocytic
mycelium, naked plasmodium like thallus
which lacks rhizoids.
• Coelomomyces psorophorae are obligate
parasites of mosquitoes and chironomids
(midges) and are important biological
control agents of mosquitoes.
• It has an alternation of generation and also
heteroecious requiring two hosts [one
mosquito larvae; Culiseta inorata-
sporophytic thalli diplophase (2n) and
other a copepod; Cyclops venalis-
gametophytic thalli haplophase (n)] similar
to rust fungus in Basidiomycota.
• Zygote (A)
• Larva of Culiseta inornata (B)
• Sporangia (C)
• Zoospores of opposite mating type (D)
• Cyclops vernalis (E)
• Gametes of opposite mating type (F)

11. Abdomen of Simulium piperi with Coelomomyces.

12. Zygomycota
Weeds of the fungal world
Mostly saprobic, some are Facultative parasites
Production of metabolites

13. General Characteristics
• Thallus is well developed with branched mycelium consisting of coarse
grey or white coenocytic hyphae.
• Cell wall is composed of chitosan, chitin, a partially deacetylated form
of chitin.
• Tufts of rhizoids (hold-fasts) are formed as anchoring organ just below
the sporophore.
• The intervening hypha connecting two groups of rhizoid are called
stolon.
• Asexual reproduction by aplanospores (non-motile sporangiospores),
conidia (Entomophthorales); also by budding, oidia, arthrospores and
chlamydospores.
• A typical zygomycete sporangium is relatively large usually columellate
borne terminally on a specialized hypha called sporangiophore.
• Sexual reproduction results in thick walled resting spore called
zygospore; developed within a zygosporangium which is formed after
a fusion of two gametangia.

14. Zygomycota
Domain - Eukarya
Kingdom - Fungi
Phylum
Subphylum
Family
Genus
Mucoromycotina Kickxellomycotina Zoopagomycotina Entomophthoromycotina
Zygomycetes Trichomycetes
Mucorales Endogonales
Entomophthorales
Mucoraceae Pilobolaceae
Endogonaceae
Mucor
Rhizopus
Pilobolus
Endogone
Order
Class
Entomophthoraceae
Entomophthora
Class
Order
Family
Genus
Genus
(Kirk et al., 2008)

15. Mucorales
• Fungi in this order are widely distributed in soils and mostly saprobes;
some may cause spoilage of food.
• Some are facultative parasites of plants and animals, while others may be
obligate parasites on other fungi, especially on other Mucorales and
mushrooms.
• Mucorales are commonly known as ‘pin molds’ because of their sporangia
that appear as black dots in the cobweb-like hyphae, are often the first
species that participate in decay of vegetable matter and other substrate,
hence called “sugar fungi”.
• They utilize simple sugars most efficiently leaving complex
polysaccharides (cellulose, hemicelluloses, pectin etc.) as they lack
enzymes to degrade complex carbohydrates.
• The phenomenon of heterothallism was discovered by an American
mycologist/geneticist Dr. A.F. Blakeslee in 1904 in Mucorales (Mucor
mucedo and M. hiemalis)
• The pheromones initiating sexual development in Mucorales are mating-
type specific and function as precursors of compounds known as trisporic
acids.

16. Family: Mucoraceae
• This is one of the largest families of Mucorales.
• It contains genera Actinomucor, Mucor, Rhizomucor, Rhizopus, Parasitella,
Zygorhynchus and Circimucor.
• Members are either homo or heterothallic and produce multispore columellate
sporangia with persistent walls.
• Species of Mucor and Rhizopus cause post harvest rot in fruits and vegetables.
Ex: R. atrocarpi causes fruit rot of Jack fruit
• Rhizopus stolonifer occurs very frequently on bread and hence called Bread
mould.
• Due to pin head like black coloured sporangia the entire mycelium appears
blackish and hence the name “Black mould”.
• Mucormycosis is caused by M. circinelliodes, M. javanicus, M. racemosus, M.
ramosissimus and M. spinosus.

18. • Some of species cause soft rot of sweet
potato Rhizopus stolonifer (Black rot of
sweet potato) in storage.
• Choanephora cucurbitarum is plant
pathogenic that attacks flowers and fruits
of cucurbits and many other
economically important plants often
causing considerable damage (rotting of
green vegetable peas, beans, cucumbers
etc).
• Rhizopus stolonifer can also be very
destructive to strawberries during
shipping and marketing.
• Mucor racemosus causes storage rot of
fruits and vegetables.
Structure of Rhizopus

19. Rhizopus arrhizus
Rhizopus microsporus
Rhizopus stolonifer

20. Mucor Rhizopus
1. Habitat: commonly found on dung Commonly found on bread
2. Structures like rhizoids, stolons are
absent
Structures like rhizoids, stolons are
present
3. Sporangiophores variously branched
with a single terminal columellate
sporangium
Sporangiophores unbranched, short,
stout with single terminal columellate
sporangium
4. Gametangia are of same size Gametangia are of unequal size
5. Food material is absorbed by entire
mycelial surface
Food material is absorbed by rhizoids
6. Aplanospores adhere to columella with
drop of fluid, not easily disseminated but
disseminated by insects and ants.
Aplanospores easily disseminated by
wind
7. Columella do not change its shape after
spore liberation
Becomes dome shaped after spore
release

21. Family: Pilobolaceae
• It includes three carpophilus genera, Pilobolus ( Hat thrower, shot gun fungus or
Circardian clock), Pilaira (isolated from dung of herbivores), Utharomyces (from
rodent faeces), rarely found in soil.
• All species produce phototrophic, unbranched sporangiophores that arise
directly from the substrate and terminate in dark flat columellate sporangia with
persistent cutinized walls covered with crystals, probably composed of calcium
oxalate.
• Pilobolus has a growth requirement of dung extract and it is unique in Order
Mucorales for its forcible discharge of sporangium for a distance up to 2 m or
more.

23. Order-Endogonales
• Formerly this order included the forms that were both saprobic and
mycorrhizal, however, the endomycorrhizal taxa now belong to Glomales.
• Endogonales contain single family Endogonaceae containing genera
Endogone and Sclerogone. The sporocarps contain only zygospores and
sporangia are unknown.
• The sporocarps of Endogone has distinct odour of onions, burnt sugar or
fish.
• Both genera can be found in soil, rotting wood, sphagnum or other plant
material as saprobes or ectomycorrhizal associates.
Sporocarp of Endogone pisiformis Zygospores of E. pisiformis

25. Subphylum : Entomophthoromycotina
• Encompasses a group of biologically
important fungi best known as insect
pathogens.
• But many are saprobic in soil, litter and
dung and one genus is parasitic on
gametophytes of ferns.
• The host specificity and relatively rapid
killing of hosts makes Entomophthorales
important biocontrol agents.
• Mycelium divided by septa turns into uni-
or multinucleate segments termed as
hyphal bodies.
• Sexual reproduction involves the union of
two hyphal bodies and form thick bi-
layered zygospore.
Entomophthorales

26. Entomophthora
• A familiar species Entomopthora muscae, commonly called Fly
fungus, found on dead house fly, causes ‘Fly cholera’.
• Healthy flies contact the sticky conidia and get infected.
• Entomopthora maimaiga is used as a biocontrol agent against gypsy
moths

27. THANK YOU