3. Table of contents
ā¢ Introduction
ā¢ Salient features
ā¢ Characteristics
ā¢ Classification
ā¢ Somatic structures
ā¢ Basidium
ā¢ Asexual reproduction in basidiomycetes
ā¢ Basidiocarp
4. Introduction:
ā¢ Basidiomycota is the second largest phylum of kingdom fungi.
ā¢ Approximately 30,000 species
ā¢ The diagnostic character of this phylum is the presence of a
basidium bearing basidiospores
ā¢ The basidiospores are produced on club shaped cells called
basidia
5. Cont....
ā¢ Basiodiopores in basidiomycota are produced by exogenously.
ā¢ The basidia bearing bodies of the basidiomycota vary from
different in different species
ā¢ The minute pustules of the species of puccinia(uredinales).
ā¢ The flat geletinous films of many species of exidiopsis , the
large perennial, flattened, horse hoof shaped basidiocarps in
species of Ganoderma
6. Salient features:
ā¢ The presence of clamp connections
ā¢ Dolipore septa
ā¢ A double layered wall
ā¢ Lamellate
ā¢ electron opaque in electro microscopy
7. Characteristics
ā¢ The most conspicuous and familiar
Basidiomycota are those that produce
mushrooms, which are sexual reproductive
structures.
ā¢ The dikaryotic phase interspered between
plasmogamy and karyogamy .
ā¢ Major division of the kingdom fungi whose
members are characterized by the presence of the
basidium.
8. Cont...
ā¢ Basidia means '' little pedestral''
ā¢ Basidiomycota commonly called club fungi
ā¢ Fruiting bodies are popularly know as mushrooms and
toadtools
ā¢ The absence of flagellated cells
ā¢ These species have no differentiated sex organs except in the
rusts
ā¢ The sexual function is performed by the less specialized
structures usally somatic hyphae
9. Classification:
ā¢ According to Kirk etal in 2001 there are
i. 3 classes
ii. 23 orders
iii. 130 families
iv. 153 genera
v. 29914 species in this phylum.
10. Examples:
ā¢ The important fungi are
rusts, smuts, agarics,
polypoes various fungi,
false truffles, puffballs,
stinkhorns, boletes,
earthstars, bunts etc
11.
12.
13. Somatic structures
ā¢ The basidiomycota are typically mycelial but some are yeasts.
ā¢ There are three kinds of mycelia
i. Primary mycelium
ii. Secondary mycelium
iii. Tertiary mycelium
14. Primary mycelium
ā¢ On germination a-basidiospore give rise to primary mycelium
which is usually of short duration and limited extent
ā¢ The primary mycelium is branched septate and haploid in
nature with uni nucleate
ā¢ Primary mycelium is usually monokaryotic
ā¢ By the method of dikaryotization the production of secondary
mycelium occur
15. Secondary mycelium:
ā¢ The secondary mycelium is occur commonly ,often perennial
growing centrifugally year after an year and produce
basidiomata
ā¢ According to butler and jones in 1949 the mycelium of
marasmiums oreades may live up to the age of 400 years and
form basidiocarps each year
ā¢ In secondary mycelium morphogenetic changes occur and
tertiary mycelium form
17. Contā¦.
ā¢ The majority of basidiomycota are heterothallic
ā¢ About 10 percent of the basidiomycota are homothallic
ā¢ There are two types of homothallism
i. Primary homothallism
ii. Secondary homothallism
18. Primary homothallism
ā¢ The basidiomata are produced by the
germination of a single basidiospore
and there is no genetic distinction
between the two nuclei of a dikaryon
and mycelium is capable of
producing fruiting bodies
ā¢ Example
ā¢ Coprinus sterquilinus
19. Secondary homothallism
ā¢ Basidiospore are consists of two nuclei and
each spore on germination produce dikaryotic
mycelium producing basidiomata.
ā¢ Example
ā¢ Coprinus ephemerus
20. Contā¦
ā¢ The remaining 90% of the
basidiomycota are reported to be
heterothallic
ā¢ About 25% show simple type of
heterothallism characterized by 2
mycelial types
ā¢ 4 different type of mycelial are also
formed called tetrapolar species such
as schizophyllum commune
21. Basidium
ā¢ A basidium is a cell or organ that bears exogenous
basidiospores that are formed by following karyogamy and
meiosis
ā¢ Basidium is the structure homologous to the ascus
ā¢ Like ascospores the basidiospores are formed in the
basidiomycota
ā¢ A typical basidium is a unicellular, club shaped structure which
originates as terminal cell of a binucleate hypha
23. ā¢ Holobasidia
ā¢ A type of basidium that is not divided by primary septa are
single celled is called holobasidia
ā¢ For example
ā¢ Agaricus
ā¢ Phargmobasidia
A type of basidium which is divided by primary septa usually
transversely manner
ā¢ For example
ā¢ Tremella
24. Contā¦..
ā¢ Teliospore formation
ā¢ In this type of basidium development begins when thick walled
resting spore termed teliospore which germinates to form a
germ tube on which basiodiospore formed
ā¢ Example
ā¢ Rust and smut in puccinia
25. Clamp formation
ā¢ Clamp is formed on the secondary mycelium
ā¢ It is a hypal outgrowth which makes a connection between the
resulting two cells by fusion with cell division
ā¢ Clamp connection ensure the maintain the dikaryotic condition.
ā¢ It serve as a bypass mechanism
26.
27.
28. Cont....
ā¢ Cell division is restricted to the tip cells of the hyphae
ā¢ The cell sends a short lateral arcuate outgrowth that projects
towards the base of the cell
ā¢ One of the two nuclei in each cell migrates into this outgrowth
while remain with in the cell
29. Asexual reproduction
ā¢ Asexual reproduction occurs commonly in the basidiomycetes.
ā¢ It occur by budding ,fragmentation of mycelium,formation of
conidia ,arthrospores formation and oidia
ā¢ Budding
ā¢ First it produces a small protuberance on the parent cell that
grows to a full size and forms a bud
ā¢ The nucleus of the parent cell splits into a daughter nucleus
and migrates into the daughter cell
31. Conidia
ā¢ A type of asexual reproductive spore of fungi (kingdom
Fungi) usually produced at the tip or side of hyphae (filaments
that make up the body of a typical fungus) or on special spore-
producing structures called conidiophores
ā¢ Example
ā¢ Urediniospores produces in rust are form of conidia
32.
33. Arthospores:
ā¢ The hyphae of many basidiomycota get fragmented into
uninucleate sections called arthospores
ā¢ These may be uninucleate or binucleate depends upon the nature
of mycelium
ā¢ If mycelium is primary as in Coprinellus micaceus
34. Contā¦.
ā¢ Primary and secondary mycelium as in flammulina velutipes
ā¢ Secondary mycelium as in peniophora giganteal
35. Oidia
ā¢ oidia are produced on specialized, erect, hyphal
branches known as oidiophores
ā¢ These are cylindrical, uninucleate and smooth
walled
ā¢ Oidia are form on primary mycelium
36. Sexual reproduction
ā¢ Sexual reproduction is rare in basidiomycota
ā¢ Sexual organs are generally not found in basidiomycota except
i.e rust
ā¢ The essenceof sexuality plasmogamy,karyogamy and meiosis
does not take place in basidiomycetes
ā¢ Sexual reproduction is a lengthy process in basidiomycota
37. Contā¦..
ā¢ The life cycle is divided into two phases
1. Short diploid phase
2. Long haploid
ā¢ The monokaryotic phase is typically very short while the
dikaryotic phase which starts with the coming together of two
sexual nuclei during plasmogamy,predominates during the
greater part of life cycle
ā¢ It ends with occurrence of karyogamy and meiosis in basidium
and four basidiospores are formed
38.
39.
40.
41. ļ¶ Basidia produced highly organized fruiting bodies called basidiocarps.
ļ¶ These are vary in size. they may be microscopic to a meter or more in diameter
ļ¶ Basidiocarps disintegrate and release spores.
ļ¶ Such as coral fungi ,shelf fungi,puffballs are basidiocarps.
Basidiocarp
42. Hymenia
Basidia are form in layers called hymenia.
Basidioles
ā¢ Basidia contain sterile elements called basidioles.
ā¢ These are large in size than basidia .
ā¢ These structures are sterile.
ā¢ They give support to the fertile basidia.
43.
44. Economical importance
ā¢ The rust and smut causes many dieases of cereals
ā¢ Mushrooms are enjoyed by mushroom hunters and others for
food and flavour
ā¢ Puff balls and mushrooms are high food value
ā¢ The fungus clavatia contain the anti cancer substances
ā¢ Some of the basidiomycetes are wood rotters and decomposers
of cellulose and lignin
ā¢ Some members are deadly poisonous like the amanita
phalloides and amanita verna
45. Ecological importance
ā¢ Beneficial to forest ecosystem because they decompose rotten
tissues by forming symbiotic relationship with trees
ā¢ Some of them like chanterells are fungi which supplying their
partner tree with nitrogen
ā¢ Some basidiomycetes from mutalistic association
ā¢ Yeast is important in fermentation process