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CORE COURSE BOTANY-PAPER I- Biodiversity (Microbes, Algae, Fungi & Archegoniate) CBCS 2016
Vaucheria
Thallus of Vaucheria
Vegetative structure
The thallus is filamentous
...
The
filament is attached to the substratum by hepteron
...
Fila nent increases in length by apical growth
...
Cell structure
The cell wall is thin
...
The filaments are coenocytie
...
Septum is present only at the
base of reproductive structure
...
Ilk cytoplasm surrounds a large central vacuole
...
Many small
nuclei are embedded in the cytoplasm
...
Chloroplasts are small, oval, circular or elliptical
...
Nanthophylls are dominant pigment
...
Pyrepoids are absent
...
Starch is
absenttlahseeatarainultinucleate due to absence of septa
...
Germination of spore, E- germination of sporangium
Reproduction
Vegetative reproduction
Vegetative reproduction takes place by fragmentation
...
Each fragment develops into new plant
...
Zoospores: Zoospores are produced in sporangia
...
A
septum separates the tip from the filament
...
It is changed
into single multinucleate zoospore
...
Two
flagella are present opposite to each nucleus
...
The zoospore comes out through a pore
...
Then zoospore lost flagella
...
It germinates and
form two or more germ tubes
...
One of the tube acts as
hepteron
...
Aplanospore: Aplanospores are produced in terrestrial forms
...
The protoplast of sporangium is
changed into
...
Aplanospore is non-motile
...
Aplanospore develops new plants by two ways:
(a)Direct development: In this case, aplanospore germinate to form new plant directly
...
Sometimes, thin wall divides the contents of aplanospore in to
many parts
...
This stage of Vaucheria is called
Gongrosira stage as it resembles the alga Gongrosira
...
This protoplast become spherical and secretes
new wall
...
Sexual reproduction
Vaucheria has advanced type of sexual reproduction
...
Vaucheria is homothallic
...
The
oogonia are larger in size
...
It is produced on special reproductive
branches
...
It is cylindrical, tubular and hook shaped
...
The antheridium is club shaped
...
A septum separates it from remaining filament
...
The protoplast of antheridium is divided into many uninucleate parts
...
The flagella are unequal in
size
...
An apical pore is developed at
the tip of antheridium
...
The devclopment of oogonium starts
after the development of antheridium
...
These branches are present near the
antheridium
...
A large mass of cytoplasm with many nuclei
and chloroplast move into it
...
The oogonium swells and
becomes globose
...
Only one nucleus is left in it
...
A pore is produced in the wall of oogonium
...
But only one fuses with the oosphere
...
The zygote secretes thick wall and it becomes
oospore
...
It passes unfa iourable conditions
...
First division is meiotic
...
__________________________________________________________________
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CORE COURSE BOTANY-PAPER I- Biodiversity (Microbes, Algae, Fungi & Archegoniate) CBCS 2016
Ectocarpus
Systematic Position
Class: Phaeophyceae
Order: Ectocarpales
Family: Ectocarpaceae
Genus: Ectocarpus
Ectocarpus is word-wide in distribution particulary in colder seas and Polar Regions
...
Ectocarpus is found attached on sea rocks
...
g
...
coniferus, and E
...
E
...
E
...
In India Ectocaupus is represented by about 100
species
...
In some species one of the two systems may
be reduced
...
In many species of Ectocarpus, the thallus is sparingly to profusely branched, the cells are
uniseriate, joined end to end in a row
...
In many species the terminal portion
of a branch may end in a colourless hair with a basal meristem (Fig
...
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CORE COURSE BOTANY-PAPER I- Biodiversity (Microbes, Algae, Fungi & Archegoniate) CBCS 2016
Structure of Cell:
The cells are generally rectangular, uninucleate and the nucleus is placed in the region of the
central vacuole, suspended by protoplasmic threads
...
siliculosus) or many disc shaped chromatophores (E
...
1C)
...
Fucosan vesicles or granules are present in large number along with pyrenoid like bodies in the
cell
...
The cell wall is
differentiated into two layers, the inner firm layer is made of cellulose and the outer gelatinous
layer contains alginic acid
...
In intercalary or trichothallic growth meristem is located at the base of a hair (E
...
paradoxus)
...
lucifugus
...
Asexual Reproduction in Ectocarpus:
The asexual reproduction takes places with the help of biflagellate zoospores
...
1 B)
...
These two types of zoosporangia may be produced on the same plant or on different plants
...
Unilocular Sporangia:
The unilocular sporangia develop singly on tips of small branchlets
...
This cell functions as sporangial
initial (Fig
...
The nucleus of sporangial cell first divides by meiotic division followed by
many equational divisions
...
2 B, C)
...
2)
...
2 D)
...
The anterior flagellum is longer, pantonematic and directed forward while the posterior is
shorter, acronematic and directed backward (Fig
...
The zoospores discharge en-masse in gelatinous matrix through a terminal pore in sporangium
...
The
zoospores remain inactive for 30-60 seconds then become free and swim in water
...
These zoospores are haploid, they withdraw flagella and attach to the substratum by their
anterior ends
...
2F-I)
...
According to Knight (1929), Schussing and Kothbaouer (1934), rarely the zoospores released
from unilocular sporangia, show pairing and fusion but the fate of such zygotes is not known
...
The cell which functions as sporangial initial (Fig
...
It repeatedly undergoes transverse
divisions to form a row of 5-12 cells (Fig
...
Then vertical divisions start in all the cells
starting with the median cells of the row
...
3C)
...
This multicellular structure is
called plurilocular sporangium
...
3D-F)
...
128
CORE COURSE BOTANY-PAPER I- Biodiversity (Microbes, Algae, Fungi & Archegoniate) CBCS 2016
The mature zoospores are liberated from the sporangium through apical or lateral pores
...
These diploid zoospores multiply only sporophytic plants and they do not play any role in
alternation of generation
...
E
...
Sexual Reproduction in Ectocarpus:
The sexual reproduction may be isogamous, anisogamous or oogamous
...
The gametes are biflagellate, motile and are produced in plurilocular
gametangia borne on haploid or unisexual plants
...
The plurilocular gametangia are either sessile or stalked and vary in shape from ovate to
siliquose
...
The gametangial initial divides transversely to form a row of 6-12 cells
...
The protoplast of each cubical cell in gametangium metamorphosis into single
biflagellate pyriform gamete
...
129
CORE COURSE BOTANY-PAPER I- Biodiversity (Microbes, Algae, Fungi & Archegoniate) CBCS 2016
In E
...
4A)
...
The fertilization occurs between gametes from
separate plants
...
The more active gametes are
considered male
...
It is known as clump formation
...
4B) one male gamete is
able to fuse with female gamete
...
In other species of
Ectocarpus gametes from same plant can fuse to form a zygote showing isogamous reproduction
...
secundus, the sexual reproduction is anisogamous, the gametes are different in size
...
The micro-and macrogametes after liberation fuse and form zygote, (Fig
...
130
CORE COURSE BOTANY-PAPER I- Biodiversity (Microbes, Algae, Fungi & Archegoniate) CBCS 2016
In E
...
The largest megagametangia represent oogonia and the smallest micro-gametangia represent antheridia (Fig
...
The egg and antherozoids produced by the mature mega-gametangia and micro-gametangia fuse
to form zygospore
...
They
do not fuse but develop new plant parthenogenetically
...
The
two gametes of same gametangium or from two different gametangium of same thallus fuse to
from zygospore
...
The female gamete after liberation secretes a volatile sexual attractant
sirenine
...
4B)
...
The zygospore germinates after 2-3 days
...
Life Cycle of Ectocarpus:
The sexual thalli of Ectocarpus are haploid
...
The
isogametes or anisogametes fuse to form diploid zygospore
...
This forms diploid, sporophylic plants
...
The zoospores formed in plurilocular sporangia are diploid and give rise to diploid sporophytic
plants on germination
...
In Ectocarpus the sporophytic and gametophytic
plants are morphologically similar hence there is isomorphic alternation of generation (Figs
...
132
CORE COURSE BOTANY-PAPER I- Biodiversity (Microbes, Algae, Fungi & Archegoniate) CBCS 2016
133
CORE COURSE BOTANY-PAPER I- Biodiversity (Microbes, Algae, Fungi & Archegoniate) CBCS 2016
Batrachospermum
Batrachospermum is fresh water alga
...
Deep water
plants are dark violet or reddish in colour
...
The
intensity of light changes the colour of pigments
...
Vegetative structure
Thallus of adult plant is soft, thick, filamentous
...
The central
axis is made up of single row of large celk
...
These branches are filamentous and dichotomously arranged
...
It consists of a row of elongated cylindrical cells
...
There are two types of branches arise from the nodes:
a)
Branches of limited growth: These arise in whorls from the
nodes
...
Their cells arranged like
beads
...
Therefore, they form globose structure
;al led glomerule
...
These are also differentiated into nodes and internodes
and are corticated
...
Their cells are
comparatively longer
...
Their cells are bounded by two layered cell walls
...
Pit connections are
present between cells
...
Its pigments are phcoerythrin,
phycocyanin, and other photosynthetic pigments like chlorophyll a, chlorophyll b, Carotene and
Xanthophyll
...
The central cells of the axis are
connected by cytoplasmic connection
...
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CORE COURSE BOTANY-PAPER I- Biodiversity (Microbes, Algae, Fungi & Archegoniate) CBCS 2016
Fig: Batrachospermum
Growth
I
...
Transverse division occurs in the cell
...
Each of these
czils cuts off of four small cells
...
These initials
divide manv times
...
It gives the
plant beaded pattern
...
These branches produce
whorls
...
Growth of central axis: The cells of the central axis elongates very much
...
Thus they form node like structure on the axis
...
Formation of pseudocortex: The cells at the nodes produce Flaments towards downside
...
Thus they form loose covering around
thecentral axis
...
4
...
This cell produces lateral
branches of unlimited growth like main axis
...
They are
produced only by juvenile stage or chantransia stage
...
The plant may be homothallic and heterothallic
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CORE COURSE BOTANY-PAPER I- Biodiversity (Microbes, Algae, Fungi & Archegoniate) CBCS 2016
a) Antheridia or spermatangia: The male sex organs are antheridia or spermatangia
...
Mature spermataguium is thick walled, colourless and rounded
...
The protoplast of antheridium
changes into single non-motile spermatium
...
b)
Carpogonia: The female reproductive organ is carpogonia
...
Near the base of a primary lateral arises a 3-5 celled special branch of secondary order
...
The terminal cell of which is carpogonium
...
There is the basal dilated portion which contains the egg nucleus
and a distal part known as the trichogyne
...
Fertilization
The spermatium falls on the surface of trichogyne
...
It fuses with the female nucleus to form zygott
...
First division is reduction division
...
Cystocarp formation: A protuberance is produced on the carpogonium
...
Septa separate this protuberance from carpogonium
Fig: A-C Antheridia, carpogonium and Fertilization
D
...
Remaining nuclei migrate to them
...
The carpogonium with gonimoblast P
laments are called cystocarp
...
Formation of carpospores: The terminal cell of gonimoblast Hament produces non-
motile carpospore
...
3
...
It settles on suitable environment
...
A
small outgrowth is formed from one side of carpospore
...
It divides transversely for many times to form prostrate filaments
...
Therefore, this stage of
Batrachospermum is called Chantransia stage
...
This stage reproduces by for
ation of monospores
...
Formation of monospores: The terminal cells of filaments form monospore
...
They are produced in monosporangia
...
They become spherical and oblong to form
monosporangia
...
These spores librates and again develop chantransia stage
...
They ive rise to adult plant
...
...
These gametes unite to form diploid
zygote
...
“I he zygote nucleus divides meiotically and gonimoblast nuclei ,ire formed
...
These develop carpospores this plant is
called Ca rposporopbyte
...
The carpospores germinate to produce Chantransia stage
...
137
CORE COURSE BOTANY-PAPER I- Biodiversity (Microbes, Algae, Fungi & Archegoniate) CBCS 2016
Thus there are two haploid phases are formed during the life cycle of Batrachospermum
...
They alternate with one diploid phase called zygote
...
138
CORE COURSE BOTANY-PAPER I- Biodiversity (Microbes, Algae, Fungi & Archegoniate) CBCS 2016
Economic Importance of Algae
1
...
Algae are taken in several ways according to the choice and taste of the people
...
Some are added for flavour to various dishes, while extract from others is taken as a
beverage
...
Commonly used species, are mostly marine, and they belong to Chlorophyceae [Ulva
lactuca (Sea lettuce), Enteromorpha compressa, Caulerpa racimosa, Phaeophyceae (Laminaria
saccharina, Alaria esculenta, A
...
, Durvillea sp
...
umbilicalis, P
...
] and Cyanophyceae (Nostoc sp
...
‘Aonori’ is a
preparation of Monostroma, ‘Kombu’ of Laminaria and ‘Asakusa-Nori’ of Porphyra tenera
...
Every year 4000-5000 metric ton of dry weight of the algae is produced and it fetches
more money than any other marine products including whales, fish etc
...
It is cultivated more like a
crop plant which has resulted in the development of a more stable economic crop
...
The salient feature of Chlorella is that the cell is rich in protein and vitamin contents
(Single cell protein, SCP)
...
It contains vitamins C, pro-vitamin A, thiamine, riboflavin, pyridoxine, niacine,
pantothenic acid, folic acid, inositol and p-amino benzoic acid
...
potassium, magnesium, sulphur, iron, calcium, manganese, copper,
zinc and cobalt
...
139
CORE COURSE BOTANY-PAPER I- Biodiversity (Microbes, Algae, Fungi & Archegoniate) CBCS 2016
2
...
In Norway, Rhodymenia palmate has come to be known as
‘Sheep’s weed’since sheep are very fond of this particular alga
...
, Sargassum sp
...
, are equally liked by the catties
...
Eggs, from hens fed on sea weed meal, have an increased iodine content while increased
butter-fat content of milk is reported from cattle whose diet is supplemented with sea-weed meal
...
Pisciculture:
Algae, both floating and attached forms, marine as well as fresh water, provide the primary food
for fish and other aquatic animals
...
In many countries pond culture for fishes has been taken up and
they are fed with various forms of algae
...
Fish food is mainly the planktons (the floating forms),
phytoplankton’s and zooplanktons
...
It is now known that several vitamins found in fish can ultimately be traced to the
phytoplankton’s on which they feed
...
At the same time, these algae keep the water habitable for fishes by absorbing the
carbon dioxide and enriching water with oxygen by the photosynthetic activity
...
Fertilizers:
The large Brown and Red algae are used as organic fertilizers, especially on land close to the sea
...
A concentrated extract of seaweed is also
sold as a liquid fertilizer
...
are
used profusely for liming the soil
...
However, the greatest utility of the algae, as a friend to the farmers, is seen in some common
forms belonging to Cyanophyceae for their capacity to fix atmospheric nitrogen and thus
enriching the soil
...
of ammonium sulphate per acre (Watanabe, 1959)
...
of nitrogen fixed /acre/crop (Singh, 1962)
...
In India, the nitrogen-fixing blue-green algae play a
part of tremendous importance in maintaining the fertility of the rice fields
...
Reclamation of Alkaline, ‘Usar’ Land:
In India, vast tracts of land cannot be cultivated for crops because of high alkalinity of the soil,
commonly known as ‘usar’ soil
...
Exactly all
these functions are carried out by the blue-green algae
...
According to R
...
Singh (1950), these algae can be of use in the
reclamation of the ‘usar’ lands
...
After a year of such reclamation, the pH fell from 9-5 to 7-6, organic contents increased from 365% to 59-7%, nitrogen contents from 30% to 38-4%; exchangeable calcium from 20% to 33%
and water holding capacity of the soil is also increased by 40%
...
This method of reclamation is
now being practiced widely
...
Binding of Soil Particles:
Algae act as an important binding agent on the surface of the soil
...
The role of Cyanophycean members as a pioneer in colony formation and thus in soil formation
is well known
...
Commercial Products:
Many forms of marine algae, Phaeophyceae and Rhodophyceae, are highly valuable for certain
commercial products, chiefly agar-agar, algin or alginic acid and carrageenin
...
Agar-Agar (Agar):
Agar-agar is obtained from various species of red algae for e
...
, Gelidium corneum, G
...
It is a non-nitrogenous
141
CORE COURSE BOTANY-PAPER I- Biodiversity (Microbes, Algae, Fungi & Archegoniate) CBCS 2016
extract obtained almost in a pure mucilaginous form
...
The algae are collected, bleached and the mucilaginous matter is extracted with water under
pressure
...
The important use of agar is in microbiology and tissue culture (in the preparation of culture
media for growing algae, fungi and bacteria in the laboratories)
...
It is also used as food and in the preparations of ice-cream,
jellies, sweets and baking
...
Carrageenin:
This is a metabolic product similar to agar, obtained from Chondrus crispus, Gigartina stellata
and Iridaea laminaroides
...
g
...
, as an emulsifying and
suspending agent, in the baking, dairy industries and in clarifying liquors
...
Algin and Alginates:
Algin is a calcium magnesium salt of alginic acid present in the intercellular substance of the
Phaeophyceae
...
Its salts are used in the manufacture of variety of goods ranging
from ice-cream, salad cream, custard and jams to cosmetics, films, fabrics, ceramics and textiles
...
The production of algin by the Phaeophycean members varies from species to species and genus
to genus besides the seasonal variations in the contents, the values being highest in the winter
and lowest in the summer
...
Species of
Laminaria, Ascophyllum, Macrocystis, Nereocystis, Ecklonia, Durvillea and Sargassum are the
chief sources of commercial algin
...
Medicinal use:
Alaria was once used for strengthening the stomach and restoring the appetite after sickness
...
Digenia simplex, a Rhodophycean alga, provides an antihelmnitic drug
...
12
...
The antibacterial
effects are more pronounced against coliforms and other related intestinal bacteria
...
Several algae, e
...
, Halidrys, Pelvetia, Laminaria,
Polysiphonia, Nitzschia and Hapalosiphon, have been reported to possess antibiotic or
antibacterial properties which, however, need further confirmation
...
Sewage Disposal:
Sewage disposal is one of our main defences against those diseases which are spread by the
agency of human waste
...
Sea side towns can dispose the sewage directly into the sea but
in other cases the sewage should be treated before disposal
...
The most
important and common physical processes are straining and tedious
...
e
...
Sewage disposal treatment is essentially a process of biochemical oxidation and its basic
requirement is oxygen
...
O
...
In other words, we may say that the ever present bacteria break down the sewage into its
components complex organic compounds into such simple inorganic compounds as ammonia,
carbon dioxide etc
...
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CORE COURSE BOTANY-PAPER I- Biodiversity (Microbes, Algae, Fungi & Archegoniate) CBCS 2016
This oxygen demand may be supplied artificially which is quite expensive or through the agency
of the photosynthetic algae which grow in sewage disposal ponds The purification of sewage is
designed to render the organic wastes present in the sewage harmless and inoffensive
...
The most common algal species present in the sewage oxidation
ponds are Chlamydomonas, Scenedesmus, Chlorella, Euglena, Eudorina and Pandorina
...
Moreover, ammonical wastes have a high oxygen demand and these algae which are the
effective photosynthetic oxidizers use ammonia to build up their protein
...
1)
...
As the algae utilize the minerals and carbon dioxide, made available by bacterial activity,
the sewage becomes more and more alkaline
...
Now-a-days, sewage is regarded as a raw material carrying some basic requirements for
fertility—nitrogen, phosphorous, potassium and water
...
Tests have shown that the algae recovered can be used as animal food and in certain regions it
may be a valuable source of fodder (Round, 1966)
...
Algal cells along with the effluents are also used to enrich the
soil, in the cultivable lands as manure
...
14
...
15
...
Silica, the basic constituent of glass and granite rock, is
deposited on the cell walls of the diatoms
...
Deposits of fossil marine diatoms over 1,200 feet thick are known
...
Now-a-days, for its hard and chemically inert nature, kieselguhr is mainly used in
insulation, as a filtering agent and as an abrasive, in the industrial filtration processes of sugar
refining, brewing and wine making, in the recovery of chemicals and for removing waste
mycelium in the production of antibiotics
...
It is also used widely
to absorb coloured substances from oils and other liquids; as a cleaning powder in soaps and in
metal polishes
...
Other Products:
From members of Phaeophyceae, two important products mannitol and fucoidin are obtained
...
and fucoidin is used as a
mucilage and in medicines
...
It is also used as a source of soda in the manufacture of soaps,
glassware and alum