Sexual Reproduction in flowering Plant
-
Re-fertilisation
-
: Structure and
Eventb
-> several hormonal and structural changes are initiated which lead to the
differentiation and further development of the floral primordium
-> Inflorescences are formed which bear the floral buds and then the flower
Structure of FLOWER
-> Flowers are morphological and embryological structures and the sites of Sexual
Reproduction
-> In flower, the male /Androecium)and female (gynoecium)Reproductive structure
differentiate and develop
↑
Androecium
-Androecium consists of a whorl of stamens.
-Their Number and length are variable in flowers of different species.
-A stamen has 2 parts.
(a)Filament: The long and slender stalk, Its proximal end is attached to the thalamus or the
petal of the flower.
(b)Anther: The terminal and typically bilobed Structure.
Each lobe has 2 theca, they are dithecous often a longitudinal groove runs lengthwise
separating the theca
Female reproductive organ .
&
Stigma
style pistil
ovany
X
-> One pistil -monocarpellary e. g. mango
-> More than one -> multicapellay.
e. g. Strawberry
More than one pistil
fused >
-
syn carpons
free >
-
Apocarpus
=
structure of pistil
Stigma
sa
Hi
jLo
Fitte -
Ifeste
placente
Finda
-
A
or
0o
leman
*
yoran
ovany
>
-
Basal enclosed part of carpel
termed as Locule
Ovarian
cavity is
>
-
-> Encloses ovule
(Megasporangium) in it
>
-
ovules are attached to cushion like
structure called placenta
Style &
Stigma
↓
located at the exposed
of
end
style .
>
-
receptive surface of
pollen grains
Structure of
Megasporangium
- Chalazal
·
ro ens
AMC integument .
Nucellus
Embryo sal
=-
=
O
Angiosper ]
ovule
Gymnosperm
ovule
ovule are located ovules are not
inside the located in ovay
.
overy
ovules develops into A
taked
. seeds
seeds inside fruit
after fertilization
Double fertilization Kupe
Fertilization
Megasporogenesis .
ovules differentiate to form one
Megaspore Mother cell (MMC) .
MMC meiosis
undergo
zu
Reductional division
2n - m
haplaid Megaspores
are formed .
one of these
megaspore
develops into female
gametophyte
Nucellus is In
spe
MMC is zn
formation
Embryo Sac
the functional megaspore
only
develops into the female gameto.
phyte
-
Female
gametophyteEmbryo is sae
Monosporic development
-
.
Megaspore > gametophyte
-
- -
miotic
Nucleus > 2-Nucleate
embryosac
j
-
8 8
miotic
division
w
4-nucleate
embryo sa
>
-
>
:
mic
in ⑨
8 Nucleates Embryosa ~
After 8 nucleate
embryo sac
it make cell wall
when cell wall formed then
is
we
get embryo sac (female gametophyte
Swuchut
Embryo Sac
Chalaz al cellwall 7 cell
Y
>
-
ens
L >
-
Antipotal
no cell wall
cell
· [Egg-
~
X
micropyla est
synergifs
11
9 Pey filiform apparatus
tube
guide pollen
Pollination
>
-
Gametes are non-motive
Pollination brings together male and female gametes for fertilisation to
occur
Transfer of pollen grains from anther to stigma
-Self pollination
Self-pollination occurs when the pollen from the anther is deposited on
the stigma of the same flower, or another flower on the same plant
-Cross pollination
Cross-pollination is the transfer of pollen from the anther of one flower
to the stigma of another flower on a different individual of the same
species
r
Pollination
-Pollination occurs with the help of pollinating agents like wind,
water, insects, birds
Autogamy
-Transfer of pollen grains from anther to stigma of the same flower
Chasmogamous flower
Cleistogamous flower
Chasmogamous flower
>
-
Exposed anther and Stigma
> do not at
-
sync same time.
flower
Cleistogamous
>
-
closed flower
> Anther &
Stigma lie
very
close to
-
each other
> are
-
autogamous
Viola
> e
.
g El
polygala
-
.
Adr : -Not dependent on pollinators
DisAdv : -Cow genetic diversity in the
species .
Geitonogamy
Transfer of pollen grain from
anther to stigma of another
flower of same plant .
It is
functionally
self
cross pollination
a
genetically pollination
Xenogamy
transferofpollengrainsforeent
plant
.
cross
pollination
Man a
Pollinating agents &
Agents which carry pollen grains
from anther to stigma of same)
sifferent plant
-
Biotic : -
Insects ,
Birds
-
Abiotic-wins ,
water
Pollination wind
by
characteristics of a
-
plant polinates
wing
by
① Light pollen grains
⑧
&
③
non-sticky pollen grains
④ Large
well-exposed stamens
8
e corn
Feathery
COD
Stigma
g
. . .
Pollination water
by
less common more of polination
Algae e
.
g
-
Female flowers reach the water
surface stalk make
by a where
gametes were
already released .
e valliseria
.
g
.
Female plants in
remain
Submerge
water where male gametes are
releaset
sea grass .
In both wind a water
·
not colourful
very
are
to not produce nectar
E -m
Pollination
by Biotic Agents
>
-
Insects pollinated plants
>
-
Animal pollinates plants
.
Bees are the most common biotic
polinating agents
Insect/Animal pollination
-
Colourful -
-fragrance-
-
Nectar --
-
pollen grain /generally sticky
Yucca plant-moth relationship
helps the flower
moth in
pollinating
-
moth deposite eggs in the locule
of of flower
~
ovary
Outbreeding devices
Devices that discourage self
pouin-
attan and
encourage cross-pollination
pollen releaseond stigma
are not synchronised
receptivity
The anther placed
&
stigma are
at different positions
self-incompatibility
production of unisexual flowers
betw
compatibility pollen 2 pistil
compatible
Inhibition of the
incompatible pollen
pistil the
ability
has to
recognize
pollen
compatible pollination > post -
pollination event
Pistil accepts the pollen
formation of pollen tube
pollen tube reaches
ovany
pollen grains
↑
more into pollen tube
pollen tube enters a
synergif through
filiform apparatus
Artifical
Hybridization
>
Technique where desired
only for
-
pollen grains are used pollination
a fertilization
Emasculation
To cut anther from it
Bagging
Dusting
Broccoli
Fertilization in a
flowering .
plant
fuse
one male gamete with
egg cell
formed
zygote -
is
is called
syngamy
This
other male
gamete fuse with
polar nuclei
endosperm cell (PEC)
Primary
formes (Triploit) (Triple fusion)
is
synergits degenerate
Antipodal will degenerate
Double futilization is Jone in
flowering plant .
Post fertilization event .
Events
following touble fatilization
are called pos +
-
fertilization .
events
① Development of>framzygote
emmyo
①
11
-"I
Endosperm
11 -
PEC
③
/1 of fruit from
from overy
④ 12 " sees ovule .
Endosperm (Ilhana Kaknazana)
PEC
undergo repeated divisions
Triploid endosperm tissue is formed.
Provides nutition to
developing
embryo
Pea ,
ma nai hot
endosper ,
ae consume
thai jai
coconut ma ensospem sai jai
7
I
Ohe ,
water 4 cream In site Coconut
is
endosperm Kernel
Free-nuclear endosper
of
Most common
type endosperm
development .
Primary Endosperm nuclei
undergo
form free nuclei
repeated divisions to
Later cell wall is formed
Entosperm becomes cellular
Kernel
~ Frspem
zt
Y met
⑧
of
Types seed .
Endospermic non-Endosperic
Seef Seed
Albuminous Non-Albuminous
wheat rice Dec beans ground not
Embryo development
-
-
opp
YU.
·
M >
-
Embryogeny
·
zygote
·
·... ⑧
heart shaped
Dicotyledonous embryo
Plumule Epicotyle
&T
&
cotyledons
·
·
-
seed leauses
Foodstorage Hypocoty
Provide
nourishment
r
3
to the
Raside
vaside & plumule .
main axis of the whichRootcap
embryo
.
divites it into different regions
(j
Chalaze-
> vis Antipobal
~
nuclei
-polar
Fit > Fec
eg
T un un> Micropyle
synergic
Amy fentize
O
*
L
⑧
I
un
Des Aubrey
T Polyembuge
O
-
o
